You could also test it yourself if you have some lower level crew.
Use LVL 60-65 Supports along with some LVL 80-85 Supports on the PBB for the same battle. Or use lower LVL Gunners along with higher LVL Gunners, again about 20 levels difference. The lower Supports and higher level Supports should have different EXP for their different LVLs. The same goes for the Gunners. But, you can not compare Supports to Gunners as they get different EXP rates.