Another relevant aspect of the Z system is the ease of making bespoke adapters for it. Here are two easily build ones, left an M42-Z and right F-Z version, respectively. Both are quickly made from existing parts and a factory spare Z mount, of which I secured a good supply.
The M42 is for attaching helicoids for lenses that need a short register distance, such as the CRT Nikkor-O 55mm f/1.2. The compact F-Z is for attaching the Z body to an existing F-mount bellows or similar without incurring the overhang of the FTZ adapter. In my case, the robust PB-4 bellows device.