So I extensively tested this mod in my own game lately and I'm considering lowering the default cost increase from 350% to 225%.

The reason is this:
- You generally need more specific assembler setups to make any quality products, so in a way the +350% increase is a hardcore mode, which might be something not everyone wants.
- You pay the cost whether you get the upgraded item or not. In Vanilla you at least get low quality items out of it.
- You can not just plug in a few random quality modules into a station and forget about it.
-- This is intentional, but it also means that you have access to fewer quality products.
- Upcrafting quality modules is core to the early game in Vanilla, but in this mod it is actually extremely resource consuming that it only really starts making sense in the late game. This generally means you are stuck with "Normal" Quality modules until the late game.
- The higher quality skip chance in vanilla also means that you sometimes randomly "save" resources because they are already a tier higher.

I would like to hear from other people what their experience with this mod and it's settings are.

For my experience, I did significantly lower the crafting increase. I did some ballpark numbers (which I know are slightly inaccurate, but hopefully are close).
I do very much appreciate you providing settings allowing players to choose the time and ingredient cost we want to play with!!

350% felt very punishing when I started initially; I have only unlocked epic quality and for a generic crafting flow (ignoring productivity, which I know can be a significant boost):
- assembler (normal -> uncommon)
- recycler (uncommon -> rare)
- assembler (rare -> epic)

200% increase

at 200% increase, for one epic unit you need (reversing order above, and assuming near-100% quality increase via the epic modules I have available)
- 3x rare ingredients -> one epic
- recycler 25% times 200% means 36 uncommon -> 3x rare
- 108 normal -> 36 uncommon

so that's 108 units required to get a single epic item out.

100% increase

at say 100% ingredient (double normal), this changes to:
- 2x rare -> 1 epic
- 25% recycler * 2x = 8=16 uncommon
- 32 normal = 16 uncommon

Depending on your threshold for waste and supply of raw materials, maybe 100 units (or more) thrown into the sacrificial quality pit is acceptable to you, but having 1% of your input come back as the desired item feels quite time-consuming and wasteful, imo. (Sure, you can argue all the free resources from Vulcanus, Gleba, and Fulgora offset that, but to me, time is the most valuable resource, and I'd argue that the 3% return at 100% increase and 50% time increase is the lowest ROI I personally find tolerable.) I recognize if you apply quality earlier, to the input items, you can reduce this via productivity modules, but given that if you have less than epic quality modules, you may not even get up to the epic tier with this particular crafting sequence, so in my mind those roughly cancel out.

Recycling

As another post pointed out, the cost increase also applies to recyclers. At 100%, you have to recycle two units for a 25% chance of getting the increased quality of one units' worth, reducing it to 12.5% of input materials. This is extremely painful in the early game especially, and at higher qualities means a lot of waste for a chance of getting smaller and smaller percentage efficiency increases. While the exorbitant cost makes sense lore-wise, for those of us chasing the shiny legendary badges, it results in a lot of waste + time. Again, in-game-universe, this does make sense and I wouldn't hold it against anyone for agreeing with/sticking to the decisions Wube made in the original quality design of making legendary items incredibly expensive to acquire.

If the recycler cost were to be excluded, such that only one input unit is ever required, the 200-300% cost increase seems much more reasonable to me, as inputs would scale linearly rather than exponentially (if my numbers in this are right, which they very well may not be).

So I would definitely say lowering the default makes sense IMO, especially since (I, and I imagine many others) like this mod as it makes quality much more approachable, consistent, and potentially lowering the upfront resource and time cost to start up a quality factory.

Really appreciate all the thought and effort you put into making this! It's definitely made the quality aspect of gameplay much more enjoyable and useful for me!

Thanks, that gave me the confidence to make more significant changes to the mod. I was a bit worried that maybe I am just not a hardcore enough player to really judge this.

Glad my experience helped! I've definitely played quite a lot, but definitely not as experienced or fanatic as some 😅
These sorts of things always take time to refine, and fortunately it's easy enough to tweak as needed -- allowing players to choose their own experience is the most important, which you already have included!

Just spotted this mod in the feed and it got me thinking about how a no-gambling concept might be implemented.
First, I really like the vanilla Quality difficulty, meaning the whole process of upcycling to eventually get up to Legendary is a very good challenge. The difficulty should remain but how to take the element of chance out of it...

How about this as a way of keeping the Quality 2 and 3 modules relevant:

Rather than CHANCE, replace that number with a corresponding cost increase in the recipe. This is similar to how you're doing it now except the multiplier would be exactly proportional to the odds of upcycling.

For example... when Vanilla has a 10% chance of bumping up a tier, your mod would have a 100% chance but cost 10x the resources.
Or if in Vanilla your odds were 20% chance that would be a 5x resource cost.
A 2% chance would correspond to a 50x resource cost. Etc.

This would, ON AVERAGE, produce the exact same difficulty and resource usage that the vanilla game does, but rather than chance, it would be a certainty and a fixed cost. What do you think?

[edit] Of course the problem with my idea is the fact that you ONLY get the quality product for all those resources, whereas in vanilla, if there's a 5% chance of increased quality, you still get 95 of every 100 being a normal product. So you still get quite a lot of stuff that's useful rather than JUST the quality product. I'm not sure this is a good solution.