I just received a new component from Ultralight that I think very elegantly solves the problem of adding a focus light to Ikelite housings.
Its basically an arm component with a clamp on one end and a ball on the other (see attached) . The clamp end throttles around any ULCS ball joint and adds a second ball connector. The connection is rigid and in this application attatched to the UL-IKT that is directly connected to the Ikelite tray. Add to this a single clamp and one of ULCS flashlight adapters and you have a very good focus light mounted directly above the housing. In this case its totally independant from my strobes (so it won't move when my strobes move) and easy to adjust anywhere I want it. Best of all, its not in the way of anything else.
See Attached. I will get in the pool and test it tomorrow, but it seems to work perfectly so far.
You can see this configuration on the ULCS website: