In my reading on MR I thought the consensus was that Apple chose rivets for the north bridge in order to accommodate thermal expansion and contraction. Bolts would certainly prevent this sort of flexibility. That said, Pindelski and numerous others here have used rivets and I can’t say I’m familiar with any horror stories. But I also find it hard to believe the engineering team chose spring loaded fasteners for no reason.
Either way, glad you’re enjoying your Mac Pro. I am a fan of screen filters but I am past investing anything else in my cMP personally.