Hmm, in-camera digital signing ... took them long enough.
I work in the networking industry and this has been used for a while for software/firmware.
Sony's Forgery-Proof Tech Adds Crypto Signature to Photos In-Camera
Ah, I just remembered ... the Contax AX !!!. I remember when I encountered that camera I thought it was the greatest thing since slice bread ... the camera AF was in the body (film plane moved) so it could use any C/Y manual focus lens.
Hmm, maybe shoot in RAW with software like Darktable or other one which I don't remember ... rawtherapee? ... and possibly not focused, use manual focus , better lens? You got focus peaking or magifier?
I was surprised to read that the camera shot had resolution loss of detail ... I would have thought for such a large neg it would be a problem ... though I have not tried to take a digital image of one of my large format negs, so I could be mistaken??
I have had old bellows cameras that had what you describe. Was able to extend them without damage ... if the leather is brittle it would have cracked by now ... never had that happen even on very old bellows.
Leather stuff I use is the same as when I was riding horses ... Lexol cleaner and...
Pull off the flat black light baffle ring.
The outter securing ring has two holes ... use a spanner and unscrew it. This will release the lens from the focus component.
You can then really see the back cell ... the securing ring has two notches. Warning, on mine it was really really tight.
That's pretty good for a zoom on a 3d printed extension tube.
Don't know about the moth
I can't really comment on bellows ... last time I had one was on a 4x5 Cambo ... but you should be able to get a cheap Maco lens in an F mount from any third party like Sigma, Tamron, Tokina ... etc.