So I've been reading a bit about how closing registers causes pressure issues and can cause more damage to the unit. I havent seen to much stuff about closing registers in rooms that do not have return vents.

So I have two zones, one that covers basement main floor (basement has a single return at the unit but then only has 1 register on the further side of the room) and my upstairs is open so I can interact with the main floor from upstairs.

I have two bedrooms on the upstairs with their own unit that has a single intake in the hallway and the two other rooms only have registers no returns. Shouldnt those be fine to close if I wanted since there is no return vent in those rooms.

When you hear about not closing registers is that mainly applicable for rooms that have return vents?