Do you want your PEI sheet to sit perfectly and easily every time you put it on the print bed? Of course you do! Print two of each of these and you should be all set. Just add 2 16mm M3 countersunk screws and a bolts to keep it nice and tight on the bed corners. Just be sure they're countersunk, because otherwise they'll smack into the beacon. I think we can all agree that would be bad.