For me (this is for a ND2 Subal housing), the solution was to pull off the Subal handles and use my old ULCS tray, bolted to the bottom of the housing, with the strobe arms coming off the tops of handles on each side of the housing. It made the rig heavier, but shifted the axis of rotation low enough to basically remove the problem of the twisting force on my wrist.
As I said, this was only a really serious problem when I was using the w/a port on an extension ring, for example with the 12-24 or 17-35 zoom (and that only on a longish trip) - because of the extra buoyancy pushed further in front of the housing, creating sort of a lever arm effect. With just a fish-eye lens (and therefore no extension ring), switching to tray-mounted handles probably wouldn't be necessary.
I used the stix arms with the dome port in early july, still using the ULCS tray and handles. Last week, shooting macro, I used the Subal handles for the first time. Seemed fine. The next test for me will be whether I can find some configuration with the stix arms that would let me go back to the Subal handles, save the weight of carrying the tray and ULCS handles.