Cool stuff. I don't know if I would trust a 3D printed plastic adapter with a heavy lens, but for some playing around with a nifty 50 or 85 mm 1.8 it would be neat. I do have access to a 3D printer at work. Only lacking the RF mount camera
Bellows are much easier to adapt to various brands because the distance from lens to backplane is adjusted by the bellows. A T/S design like this has a fixed distance so you would need a different one for each lens type. I have a Minolta T/S auto bellows III and can adapt the rear of the bellows to multiple brands of cameras but to use the lens stop down feature, it needs a Minolta lens. I've only played with it a little, I've never found the bellows lens I want for a reasonable price. I have a Novoflex Castel-XL focusing rack. With the focus bracketing of the R, the bellows may not be so useful. I use the focus rack. Its very stable. The XL is no longer made and usually found on ebay from outside the US for a premium price.