You mean case clearance? I saw an article that said there's 3.5 mm between PCB and a plate. Problem is you can't buy 4mm foam or 3.5 mm foam. 2, 3 or 5mm only.
Article: https://www.maketecheasier.com/modify-keyboard-case-plate-to-perfection/#:~:text=A large part of a,acting as an acoustic chamber.