This is a gorgeous folder which I occasionally use as a medium format option when overloaded with 35mm kit. The problem though has been the film frame spacing, the advance mechanism perfectly calibrated for Zeiss Ikon film, which was thicker than modern and, of course, not made now.
I'd heard of adding a length of Post It notes on to the film paper backing, but nothing precise, so I stuck a 6cm length on to the Kodak Tmax 400 paper backing and wound that on.
Result just out of the tank - framing perfect, just one missing shot at the start from user incompetence, but a full 12 exposures possible. Apologies for the slight out of focusness but my XT30 hunts a bit in close ups.
Start of film
End of film
Post it length and position (the latter simply to ensure it was tightly wound)
Apologies if this is a solution that others have tried, I was entertained by the serendipity of getting it right with 6cm of Post it first time! Results may well vary with other films.