Is there a way to edit planes in MP?

[Ataros]

Some QM are bugged. I copied QMs and Single missions from Steam folder into my Documents folder\Il-2\missions\single and open them with FMB to run from FMB or edit and then run it from Single missions instead of QMB.

BTW if you save your preset both as "default" and "custom" the game will have no other choice than to use them I think even in QMB. Then you can open and edit user.ini to check if loadouts are saved there correctly.