Hi Mark,
Good to see your still experimenting "outside the box" with the NEX system. It doesn't surprise me to find you here in searching for info on the Sony 90 and APS-C.
I was going to buy a fellow divers 36401 55mm N85 to N120 adapter today to come up with a combo for my NEX7 WA and SM, but than discovered after talking to Kevin at Reef, that it wouldn't work for either: 55mm most likely being too deep for my Z12 and as you pointed out, a hair too short and no centering sleeve at the end of the S90 for the Nikon macro port 60. Nor will it work for the T10-17 zoom gear. As you mentioned, the 60mm adapter doesn't have a focusing knob so using it on a Sony 90 would be frustrating to say the least given it difficult focusing and it gets worse when you use a +10 diopter in my experience.
A fairly new addition to adapters is the Nauticam 50mm N85 to N120 adapter for the Metabones and Tokina10-17 FE. Add a N120 10mm extension and you have a 60mm adapter with the focusing knob providing you have a way of making the gear work with it setting it back some 10mm. I was thinking of using this set-up for my WA using the adapter by itself for my Z12 and the T10-17 , adding my 20mm mini extension to use it with the Z16-70, all in the 4.33 SLR dome. If it works, I'll remove my 67mm swing adapter I grafted onto the shades of my mini 4.33 for SM when using the Z16-70. This macro mount works good with my 4.33 and S18-55 kit lens.
Be nice to get the 50mm N85to N120 to work with T10-17 for FE, Z12 for sharp rectilinear , Z16-70 w/ macro capability for a single dive lens set-up, and the S90 for SM. All from a couple ports, N85 to N120 50mm adapter, a 20mm mini extension and 10mm N120 extension.
Many have reported that the FE 4.33 has too much curvature and it's use is discouraged for rectilinear WA's, but my shots with my modified Z12 in my mini 4.33 look good. I find the corners nearly as sharp as the 7" dome. Perhaps because it is such a close focusing lens. The WA close up is fantastic with the 4.33, focusing on subjects only an inch or so away from the port. With the 16-70 I'm hoping for more of the same with 16mm rather than the kit lens 18mm, along with the grafted macro swing mounted to the shade wings to bring the +10 into play for SM. Focus and zoom gears are all available using the 50mm adapter, which is what has attracted me to the set-up.
On paper this seems like it may work, but given the costs I may just stick with what I have and try to manufacture a Z17-60 zoom gear that will fit the mini 4.33 dome's narrower ID and add an mini-30mm extension(along with my 20mm extension) to give it the depth it needs. I'm currently looking for some 70mm OD and 68mm ID aluminum tubing for the Z16-70. I found it in titanium, but too expensive ($70) out of China for a short piece. Where did you get your tubing from and what vacuum cleaner belt did you use when you made your own gears? Was it for the Z16-70?
I'll continue to use my Canon 60 macro set-up in Nauticam's custom port until I can figure a way to add the S90. Kevin said the S90 is long and needs a centering ring when using a adapter focusing/zoom gear, otherwise the gear pushes the lens sideways. Plus. there's the diopter distance issue mentioned above to consider. As Phil mentioned, the N100 system is the best for the S90, as it's designed with the centering ring. My Canon macro set-up works well with diopters and also has the the centering ring at the end of the lens.
Cheers,
Marsh