Nikkormat and Nikkor 2.1cm/4 Compatibility?

Can anyone educate me on which Nikkor 2.1cm/4 lenses are compatible with which series Nikkormat? I've read that some combinations will work without damaging the shutter. With MLU, of course. Thanks!

PS Speaking of the Nikon F era 2.1cm, not the RF one...

According to this, it should, but according to the Camera Quest website, "the earlier 21/4's before 225001 will not fit on the Nikkormat cameras due to internal restrictions."

https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/ultrawides/21mm.htm