Using Nauticam wet lenses on Ikelite housing

Does anyone have any insight or knowledge on the maximum gap from the lens face to the port glass for a nauticam wet lens ( SMC-1, MFO-1, MFO-3 ) to focus through?

I have a canon 5d IV that I use in an ikelite housing and located a flip adapter to allow 67mm threaded wet lenses to be used. I tried it out with a nauticam SMC-1, with bad results. I'm using a Canon ef 100mm f2.8L lens, the lens sits approx 1" behind the port glass when assembled(no way to change this) The adapter places the SMC-1 essentially right on the port glass, Making the effective distance from the lens face to the SMC about 1"

I took it out on a couple dives and I couldn't get it to focus at all, is this possibly a user issue or hardware combo issue? Im concerned the issues may be caused by the interior "gap" from the lens to the port glass

Any help is appreciated!