Yes, I know they came on their own boards but I've seen recessed boards that were made for them. No clue who made them although I assumed it was Horseman since Horseman makes clear in their literature that shorter lenses can be used but extra accessories would be necessary.
Anyway, I ran some tests to figure out if I really even need it to do what I want and I don't think I actually do. Either way, if anyone has one it could be nice to have. Regardless, thanks for the reply! If worse comes to worse and I do need it but can't find one I'll do what you said and make one.