I'll preface this by noting that I'm coming to this largely from an ATOM perspective (because that's how I got involved with this mod in the first place), but some parts will be relevant to other configurations as well. (Even less will be relevant if you're not playing with Krastorio 2.) Also, comparisons with K2 recipes assume that wood pulp is turned into wood (via pulp + resin made from pulp recipes) to get a baseline number.

The existing wood production recipes have a problem - they're kinda bad compared to the Krastorio 2 ones. The first tier is just awful. The second tier is slightly better than K2 wood from water alone, but way behind K2 wood with sand. Tier three is still behind but it's approaching defensible. And the fourth is actually super effective, but by the time you get there are you going to completely rework for it?

Now, if you're playing with BI and K2 but not ATOM you're going to say "hey wait, those numbers sound wrong". That's because in the presence of K2, BI quadruples the yield of everything. And ATOM undoes that, seeing it as too extreme. But even with it in place, it doesn't feel good IMO.

The BI greenhouse type buildings also have a problem, which is that they're much more complicated and expensive to make, and don't really offer anything in return for it. Same crafting speed, a little less energy consumption, less module slots on the nursery.

An additional factor that was brought up in discord discussion is that with large tech multipliers it can take a long time and a whole lot of chopping trees to get to the point of being able to automate wood production.

And I've got a beta test version out that makes changes to address these issues. You can find it here: https://github.com/Morganite-MLI/Bio_Industries_2/tree/Rebalance

Things changed for everyone:
-Tier 1-3 wood production recipes are much faster. These are balanced to be a moderate boost over K2 recipes of a similar level of technology and recipe complexity. Tier 4 hasn't been changed, it already seems good enough. (The intent is for these recipes to be used without the 4x multiplier, but it hasn't been removed from the code because then they would be nerfed in ATOM; at some point this multiplier will be exposed instead. I haven't coded that yet though, so in a non-ATOM K2 game the yield will be higher than intended. Of course, I'm a firm believer in Factorio Your Way, so if you want a ton of wood, you can have a ton of wood. But for your information, as it were.)
-A basic tree farm has been added. It's slow and doesn't have very high yields, but also available quite cheaply and quite early. (It's also a burner machine; don't try to feed it wood to burn unless you want a net negative yield.) The graphics come from the Zen Garden mod, which has a compatible license and was the best thing I could find for "trying to grow wood without glass or fluid handling". Though I'd prefer something that looks more mechanical as well, but... well, you can't always get everything you want.

Changes specific to games with K2:
-An option to hide the Krastorio 2 wood recipes (including the one added by AAI industries). The tier 1 BI recipes are moved to the K2 greenhouse tech when this is turned on.
(This was added because some are pushing for doing so in ATOM after the BI recipes have been improved. I'm not sold on this idea myself, but I'm also not the boss of ATOM, so who knows what will happen there.)
-An option to change the crafting speeds of the bio farm and bio nursery by a multiplier has been added, and an option that increases the energy cost of seed/sapling/wood recipes (BI and not-BI alike on the latter) by a multiplier has also been added. Both of these default to 2. These are exposed for testing purposes, and will not be visible in the final release. (Which is also why they don't have localization.)

That last one needs some explanation. This is my try for "there is a reason to switch from the K2 greenhouse to the BI buildings" - if this approach is taken, and the default numbers used, wood production will be at half speed until upgrading to the higher end buildings. To be honest, I'm not entirely satisfied by this, but it's the only thing I've been able to come up with that doesn't also boost the tier 4 recipes, which I feel like are already good enough. I very much welcome any suggestions... on pretty much any of this really, but especially if anyone has any other ideas on how to accomplish this goal.

And that's basically it, I guess. This mod has not been high in my queue for porting to 2.1 because I want to do this stuff first, but that queue is probably going to start getting shorter again, so if you've got thoughts on any of this, now's the time.

My feedback is based on being 1450 hours into an ATOM save which I don't want broken....

I remember looking carefully at all the recipes way back when and deciding that using the most basic one and boosting it beyond all reason was the way to go. My greenhouses use +1500% power and run at +600% output and take only water. It seemed a bit dubious before space based power, as I was taxing my nuclear power a bit, but was completely justified after that.

So, I agree with the 'problem' that you have identified, but ask that you don't nerf the starting recipe too much as my response at this point would have to be to double down on my current strat and post an angry face emoji.

I did like the Angel+Bobs recipe in a previous playthrough, where saplings were used. And fertiliser sounded interesting on paper. But until "late early game" I was running short of potassium nitrate and sulfur and fertiliser would have just added more demand on those resources.

What probably would have made me choose a different path early on would have been if fertiliser was 80% cheaper

So, I agree with the 'problem' that you have identified, but ask that you don't nerf the starting recipe too much as my response at this point would have to be to double down on my current strat and post an angry face emoji.

Well, that's as noted the part that's not entirely up to me. I somewhat prefer the idea of having the simple recipes available for "just need a little wood somewhere", and then the high-performance recipes for where it's worth the effort. But even though I've been doing a lot of the development, I'm not the last word, so I just don't know. I thus cannot rule out that ATOM will end up locking the option to hide the stock K2 wood recipes, meaning you just wouldn't be able to do that anymore. (Though it would also not be hard to un-lock it with a local edit.)

For my preferred outcome where that is not enforced... well, the current beta would definitely qualify as nerfing them some, although how much is up in the air. Still, I would rather not do that. The question is, how much of an advantage do the BI buildings need to have over the K2 greenhouse to make the changeover worth it? And of what form? I'm wary of throwing in too much productivity, and in general I don't want to raise the tier 4 output much, but a lower amount might be okay.

What probably would have made me choose a different path early on would have been if fertiliser was 80% cheaper

Are you looking at K2 fertilizer or BI fertilizer? In 1.1 they were conflated, but that didn't make it to 2.0, and the BI fertilizer doesn't involve anything made with potassium nitrate that I recall. Once you've got algae I'm pretty sure it's possible to make BI fertilizer in a completely closed loop using a relatively small number of machines.

Are you looking at K2 fertilizer or BI fertilizer? In 1.1 they were conflated, but that didn't make it to 2.0, and the BI fertilizer doesn't involve anything made with potassium nitrate that I recall. Once you've got algae I'm pretty sure it's possible to make BI fertilizer in a completely closed loop using a relatively small number of machines.

IF I am correctly identifying the BI fertilisers now, then yeah, no nitrate. It does take sulfur though. This was also in short supply until I discovered how profitable the loop of sulfuric acid from algae -> ash + sulfuric acid = sulfur is. I mean that I was importing sulfur from off-world until I found this recipe which had been unlocked, but I don't know how long before. So I had a very good reason to avoid making fertiliser, though it was based on non-ideal gameplay, so I can't say if this could be an issue for other people.

Hey, @ants9000, you're good at giving feedback so I'm gonna put this question directly to you. (Although anyone else is welcome to throw in their ideas.)

Supposing you were building a base using the BI wood recipes, them having been buffed enough to be good in their own right. How much of a bonus would be enough to make it worth your while to switch from the K2 greenhouse to the Bio Farm and Bio Nursery? Would a small speed or production bonus seem worth it? Does either seem particularly not-valuable?

I'm looking for a way to not nerf... well, anything, really, it sucks and I would rather not screw up people's bases if I can avoid it. There's already been enough cases where I didn't feel it was avoidable in other ATOM components as it is.

To give you my point of view too: I don't use Krasterio, although ATOM looks interesting.
I use this mod to generate tons of plastic and coal, sometimes sulfur, sulfur acid and to reduce pollution. I hope, the changes are not too heavy. I will modify my base to get the output I'm having now.
And maybe if I'm too motivated and have too much time, I could try to upgrade OreGalore and BioTech to 2.1.

If you're not using K2 then the only changes being considered should be improvements.

Although what those improvements will be remains up in the air. I'm starting to look askance at the large quantities of wood pulp produced after a discussion with cackling fiend; I find it useful but not necessarily that useful, and turning it into wood adds an enormous amount of overhead. Is getting ever-increasing amounts of it from higher tier recipes actually an improvement?

Hey, @ants9000, you're good at giving feedback so I'm gonna put this question directly to you. (Although anyone else is welcome to throw in their ideas.)

Supposing you were building a base using the BI wood recipes, them having been buffed enough to be good in their own right. How much of a bonus would be enough to make it worth your while to switch from the K2 greenhouse to the Bio Farm and Bio Nursery? Would a small speed or production bonus seem worth it? Does either seem particularly not-valuable?

I'm looking for a way to not nerf... well, anything, really, it sucks and I would rather not screw up people's bases if I can avoid it. There's already been enough cases where I didn't feel it was avoidable in other ATOM components as it is.

Well there's my "what would make me change my design now" question - and probably not much - I've run spaghetti and made a standard base for most planets.

But lets say I'm designing that again, or, go back a bit further, to when I was scaling wood production on Nauvis. Regarding the greenhouses:

Power - yeah it uses some - but frankly, who cares? I'm currently burning ALL fission fuels in several dozen reactors because I was too frugal and have no plutonium. Power was never an issue, really, though I thought it may be as it sure was in my original SE game where I ran out of fission fuels to mine.

Speed - yeah they were slow. I didn't mind though because it game me an excuse to boost them and spam them and create a very free buffer against pollution. I never used air filters.

Production bonus wouldn't be worth anything - I mean greenhouse takes water in the basic mode. with prod, it would ... take less water? But still way too much for a waterless planet. This doesn't address the BI recipes but I'll get there.

So speed would be my answer. And maybe not a small boost, but a 10x boost. Well, it is already much faster then the greenhouse water recipe - (let me check in game).

Okay. I don't really see anything wrong with the recipe as it is. It SEEMS at least as valid to use as the one I'm using. I chose greenhouse spam over complexity. But, the advantage of my setup is the minus 10,000's pollution per minute, which reduces the frequency of biter attacks (even when the pollution is spilling over the edge of the world, 30%+ is being removed by my greenhouses, so that's less biters to shoot with lasers, less lasers even needed, less power draw from those lasers, and less chance of damage). Make the recipes have a MASSIVE multiplier to pollution maybe? Possibly shorten crafting time and reduce output accordingly, for a more consistent non-belt-clogging torrent of wood every couple of minutes?

Make terraformer work faster and better, it takes an ungodly amount of time