I generally don’t retract mine to pee, I get a thicker more circular stream with it forwards. On the odd occasion I do retract, I get a more squashed stream that’s harder to direct. I have quite a long loose foreskin so I guess it acts a bit like a nozzle?
I used to have quite a tight frenulum, which maybe pulls on the end of my head when I retract and messes up the flow?
Pretty much the only time I piss with it retracted now is if I’ve either had a wank in the shower, or I’ve gone to take a piss after sex and it’s still retracted.
I once talked about this with a friend, he like me never used to retract to piss, until someone told him that he really should. So he started doing it as routine and now always fully retracts to take a leak. He has a long big foreskin too and similarly used to find it difficult to retract his, until he persisted and now has no problems getting a good stream with it retracted, he even finds that if he pisses with it forwards it makes more of a mess!