Hi Oscar.
I had tested the shift adapter today and find it - as you write - very easy to use. Mamiya should sell this item and camera as a standard kit for studio photographers.
You don'nt get a tech.camera, but a very fast working camera (as fast as a RZ can be ) with a litle tilt. Enoug for many close up studio jobs.
I have testet the adapter with my RZ 140 Macro and PhaseOne P45+. Se enclosed photo. P45 file is cropped to 4200x3600 pix.
Link to 4Mb jpg file..........Max bellow extension and max tilt. F. 22.
A: With max tilt. B: No tilt.
I find it worth to order.
Kind regards
McRepsej
Denmark