What feature do you want to see added?

I use /br scatter #fullcopy[] to paste in rocks/trees/bushes and other things into my terrain so it would be really nice to be able to
set a random rotation for them.

Are there any alternatives?

i have tried /brush populateschematic but its quite weird for me

Anything else?

nope

This isn't possible with scatter. #fullcopy already has a random rotation option https://github.com/IntellectualSites/FastAsyncWorldEdit-Documentation/wiki/Main-Commands-and-Permissions#fullcopy-schemfolderurlcopy-rotatefalse-flipfalse