One idea would be to skip manual focus and go with the much less expensive FP-120 port... Autofocus combined back focus driven "lock & rock" techniques is preferred by many users of these systems.
You could add a focus gear from XIT404 at some point in the future should you determine that actual gear driven focus is needed Some prefer the ergonomics of this solution too, driven from the knob on the housing instead of the port.
In the proto design, the stainless steel handle brackets tie in to the top of the housing with m5 screws. Strobe mounting balls could certainly go there, providing one on each side, and more options than some of the smaller housings have. A crafty user could also come up with a nice wrist strap mount tying in to that top m5 hole, and one of the bottom handle mounts.
My take on this is that more advanced users tend to (statistically speaking) want handles on both sides, and this supports that more cleanly than an optional tray system. They could certainly be removed for special configurations.
The inverted trigger style release has worked well in in the past on some housings where handles were optional, namely the old Olympus PT-E series. Given the similar form factor that may hold true here.
Nauticam Macro Port 60 + 10mm Extension (which bolts on the back) works well with 60mm /2.8D. It actually vignettes a bit on full frame at more distant focusing distances. No issues on DX though, and actually no issues at the typical distances you'd use this lens with.
The geometry of Compact Port 50 (for which there is a sub see adapter) and Compact port 30 is pretty similar (same window size, for example), and that Subsee adapter could likely be adapted.
This lens works well in pretty much everything other than the small 4" dia domes used for fisheyes. So if you have a mid-size to big dome chances are you don't need to buy anything else. But if I were setting this up from scratch I'd use a 170mm optically coated glass dome w/ 5-6cm of extension (depending upon the 17-70 variant).
My take is that this is really best left to the individual photographer... They should test both setups, and decide what works best for their own situation.
All superwide rectilinear lenses exhibit some corner softness. Some more than others. 17-35 is about in the middle.
As you know, some lenses require a diopter to focus behind a dome. 17-35 does not in Zen 230.
Single element closeup lenses narrow the fov, increase CA, and induce a strong pincushion distortion. They also tend to sharpen up corners. But how important are the corners in most shots?
Personally, I am tending to not use the diopters whenever possible, as it seems counterintuitive for me to give up the field of view and increase distortion when I don't have to. I'd rather zoom in a bit, or stop down more, in situations where corner softness will create an issue.
The current estimated ship date is May 27 from Nauticam, so a few day s later form individual dealers and distributors. There is a long preorder queue, so it will be some time after that before new orders are filled.
I had the pleasure of shooting some video last week with the final prototype.
Like all other super wide rectilinear lenses in this focal length range, corner sharpness will be a challenge if used wide open. This can be managed by stopping down, and working in the 11-12mm range instead of full wide.
I've wondered about the utility of this lens on FX a lot, set at 14-17mm. I've seen imatest results that suggest that the resolution of 10-17 is just above the D800, so while it is nearly resolution limiting, it isn't yet. Worth a test, though...
Tokina 10-17 at 14mm
Sigma 15mm at 15mm
10-17 at 14mm Center Crop
Sig 15 Center Crop
10-17 at 14mm Lower Left
Sigma 15 Lower Left
Draw your own conclusions, but I wouldn't run out and buy a new lens.