I've never shot 35mm in a folder before but I have done it many times in a Holga where a red window is also used for advancing. I just measured that it took 1.5 turns of the knob to advance it to the next frame and marked the top of the knob with two different colored marks opposite each other, and a mark on the body. I then use those for reference to count the number of half turns. It's close, the gap does get a little wider by the end as the 120 take-up spool gets more film on it. It's not much though, and easier than trying to use a sliding scale regarding number of wind clicks.
Film curl might be a worry for me, especially with older film that's been spooled for awhile. I do shoot a lot of 35mm panos in my RB67 Pro SD and now use a 3d-printed gate on the front of the back that replaces the 6x7 gate and only exposes about 26mm x 68mm of film and keeps it flat. This seems to work the best for me, and in conjuction with a mask for the viewfinder, allows for easy composition and shooting in pano format. The different film stocks available in 35mm, especially slow films like SVEMA MZ3, makes this a fun way to shoot panos. Of course when I need something larger with more detail I'll drag out my GX617.