One person should have only

one 485. Because 485 is related to A#, finger printing, FBI checking, VISA number after approval etc. So you can not have two sets of them. Actually, when you submit your 485, they will check their system to make sure that you don't have former 485. Or else, they will just update the old one, if not returning your later submission. So From every aspect you should not submit more than one 485.