Yes, unfortunately. Trickiest part is to make sure the tightening ring is not over tightened (this wrinkles the diaphragm), and there are no debris between the diaphragm and the backplate. This is tricky as the diaphragm can't be seen properly under the front grille/plate. I have done reassembly several times without the grille/plate in order to make sure everything looks nice. I eventually assembled everything once I was certain no dust was trapped under. Measurements also confirm all is good. This is particularly challenging with stock spacer because it is so slim. Also important to remember how the holes between the metal and plastic transparent backplate are NOT ALIGNED!
In theory the slots can be drilled through or filed without disassembly, but you have to make sure no debris is left behind.
