Not to argue, but I do disagree on a few topics.
1. Feasability: is the technology really available. Gyro stabilizers? The size of the housing would be near the old Imax camera.
Gyro's are very simple, inexpensive, and would not take up that much space or add that much weight. Remember, the housing in the water will be near neutral, so gyro's could be small. This is just throwing around some ideas. I certainly would not avoid a good housing just because it didn't have gyro stabilization.
2. Bulk: Making a housing more buoyant really means making it bigger, esp with the ALU housings.
Nobody wants a buoyant housing. We want it close to neutral without having to add too much weight or additional buoyancy. This is why I recommend building this housing with one premium do everything lens, so it will be well balanced and neutral. I don't think anyone buying an $8,000US camera and a top of the line housing would want a cheap base lens, and then add a premium lens and have it 4-5 lbs. front heavy.
3. Costs: While the bulkier housing will be great for stability in pans, it'll also cost more and travel will mean paying for shipping as well.
The EDCAM EX is only slightly heavier and larger than an FX1/Z1. Housing should be similar size.
4. Limits of Physics: Achromatic diopters are great. However to use them behind a WA lens is asking a lot. First of all, all lenses are designed to have minimal space between lens elements to ensure best quality and minimize the size of the lens element. Moving it back not only compromises quality but also forces the lens element to be proportionately bigger. Again this is pure physics.
We can at least try, right? It may be quite feasible, maybe not.
Many don't dive with lights and there are so many different systems of lighting that this makes little sense. A well balanced neutral housing, with monitor is the most desirable setup. Nowadays, many of the HID lighting systems attach the batteries to the bottom of the camera, which is why a few of you are complaining about the weight underwater.
L&M did a great job with their HID light system. My FX1 housing is trimmed perfectly with the batteries installed at all times, and I don't even change the trim weights when I mount the lights, just makes it slightly more negative, but very usable. The housing has to be designed with specific lights, which will definitely be the manufacturers lights. Get used to them, or deal with the consequences of changing them. A monitor will be a necessity with the XDCAM EX as the on camera monitor is in an awkward place for viewing with an underwater housing. The housing should be designed with a high quality monitor as standard. Will add this to the list.