Hello!
I just started walkthrough with several planet mods enabled on Marathon-like settings (science x10), tuned up biters for a bit and unchecked progressive recipes mod setting. So here are my discoveries:
1. Initial research on Lignumis appears to be much slower than first techs on Nauvis. Perhaps, the cause of this is slower burner laboratory and harder scaling up of production.
2. First physical weapon upgrade techs (damage and speed) are hard-linked to steam and wood science packs. If the player did not research them on Lignumis they become impossible to research until player enters the space stage.
3. Steam assemblers do not produce pollution.
4. Addition of early recipe of tree seeds introduces new strategy against biters: usage of artificial forests to reduce pollution and subsitute dragon teeth wall formations.
5. When I was still on Lignumis I could not destroy any biter nests even with turret creep strategy: wooden ammo was ineffective.
6. Basic gun turrets get more damage upgrade from corresponding tech than usual gun turrets. After several tech levels basic gun turrets deal more damage.
7. The message "Oh no! Not again!" when landing on Nauvis sounds strange. Engineer have built shody one-time wooden rocket to get to Nauvis and got to Nauvis with full health and even with all cargo. Engineer succeded – all went well.
8. In the description of wooden wall it is written that it can decrease noise pollution. I could not see it in practice – how effective is this mechanic?
9. Wood becomes incorrect type of fuel for furnace. Why?

Also, I have some ideas and suggestions:
1. Factoriopedia pages about Lignumis would be great
2. While playing I remembered another mod – Hostile trees (https://mods.factorio.com/mod/hostile-trees). Maybe it will become interesting addition to planet mechanics.

I hope that it will be useful.

Hi. First of all, thank you for the feedback.
I'll write a quick response but will not code anything until tomorrow because bed time :-)

1. I'm currently trying that out myself. I just added ignore_tech_cost_multiplier to the tree seeding tech. It'll reduce it to 10 science packs ignoring the multiplier. It will be in the next release. Yes, it's slow. I'm not sure if I should do anything about it.
2. I fixed that already. The Nauvis technologies don't have the Lignumis tchnologies as prerequisites anymore.
3. True.
4. I would say it's intended.
5. My plan was to replace the enemies with weaker ones. I didn't finish it yet. I don't like buffing the turret and ammo. They should be weak.
6. Ok, I'll have a look.
7. That's valid.
8. Very! Add at least one layer around your base. There is no direct hint in the game. You see it in the debug view. Same for belts being loud :-)

9. I had to do that because otherwise it would not be possible to prevent wood from being burned while peat is available too. There is no way of telling the game to prioritize fuels. One could argue that the furnace should be an exception as Lignumis doesn't add a recipe for wood to the furnace.

10. Indeed :-)

11. lol WTF?

Thanks for quick response. In both factorio and minecraft mods it is sometimes hard to see what is the error and what is the intended behaviour.

1. Thanks! I just loaded this save with progressive techs option off – it worked. However, there is a problem with visibility: Physical projectile damage and Weapon shooting speed techs 3 and higher do not show in available research techs and can't be found by search bar, I can choose them only manually from the tech tree.
2. I agree, replacing the enemies is better solution.
3. Oh, now I understand, why my base at Lignumis still emits sound after I departed. Funny and interesting pollution mechanic.
4. Trees sometimes spit acid at engineer or follow him, cutting a tree sometimes makes tree retaliate, etc. On a tree planet tree becomes apex predator =) Unfortunately, that mod still has no version for 2.0.

Fromt the first comment:
3. Fixed.
6. I think that was intended. It's to boost existing towers on Lignumis until you get back. Yes, it does more damage then the regular turret, but the range is shorter. Starting from level 5, the Basic gun turret doesn't get any more upgrades so the regular one gets more powerful again.

Some other things are on the todo list.

From the second comment:
1. Fixed.