Ah OK, your are no longer using the camera inside the battery housing?
Where do you install the 2" housing on the ROV?
I am looking at two quick disconnect for the analog camera signal and battery power at the back of 3" to be able to use the 3" housing (battery + camera) as a stand alone drop-down camera system (just need a frame) which can be connected to the Fathom tether.
This would add flexibility for these two different usages. I however get your point about making it more complex.
I really want quick disconnect between tether and 4" housing for all the advantages it brings. However since housing, penetrator, analog camera and voltage regulator are so cheap, I should maybe have a second independent camera system (in a 2" for example combined with a smaller battery) and dedicate it to the dropdown camera utilization and only reuse our existing Fathom tether which is the most expensive bit of equipment to bring the analog signal back to the surface.