I say that you should practice how you play, but it should only feel different, it won’t make a impact on how fast your sensitivity actually is; for those games at least.
#Aim trainer vs real game
fierce tapir
old violet
native!
eager mulch
Play Native for aimtraining.
It won't affect your sens, only the feel of it which you will adapt to very fast.
Stretched res on aim trainers won't be of any benefit. You might make things a bit more difficult for yourself too given all scenarios are build around a 16:9 aspect ratio
brittle crow
Okay