Now tell me what is the difference to the "old" way of doing ecosystems? (Screenshot)

You add the items into the list, you have the underlying material button to the right - what is really different? I think 'I do not get it where the problem lies. But probably I miss something relevant here.

Regarding the size of painted eco items - this has to do with two things.

#1 it happens when you clicked on "airpbrush style"

and

#2 when you try to paint items with a density that would go over 100%. Especially when "Limit density" is switched on as well. Then Vue tries to follow your wishes by making the items bigger - to fill more space with them.

One day your ship comes in - but you're at the airport.