top before or after last up potting

Do one first, then wait another 7-10 days before doing the other. It won't really matter which, but I woul never do both at the same time. If it were me, I would transplant first, wait a week or so for the plant to get going again, then top.

If it's going outside it won't matter much. It'll be swimming in photons from all angles and all branches will be strong branches with good buds -- assuming it is all splayed out to receive light. After a transplant, the roots take over for a bit, so i'd wait 5-7 days after or top it 3-5 days before transplant so you don't double up on the stress. Push comes to shove and calendar is a factors, i also wouldn't worry too much about doing both at the same time, but i try to avoid doubling up on such things. Easy enough to plan ahead, but context differs from one garden to the next.

It really doesn't matter what order you do it in, just get it all done well before the season kicks it into flower. You want recover time before it transitions.