It improves the stats in some way. Armor has more slots, assemblers are faster, batteries have more capacity, …

The recipe is for using quality ingredients to guarantee at least that quality output.

The modules are for the random chance of getting a quality output.

Quality batteries aren’t too hard to make and really helped with the limited space on Fulgora before I got the foundations. Same with quality furnaces and generators which produce more from the same input.

But they can? One nuke to the head works for small. Two works for medium. I haven’t come across a large yet.

Two nukes to the head did it for me.