35mm bulk is a very different thing. The film is exactly the same. Even the edge printings COULD be left the same, with rather bizarre but photographically inconsequential results.
I believe that the machinery in most packaging lines is set up to punch, notch or even cut the film at the right spot while putting the frame number on, otherwise the numbers could get out of step. Kodak did make a 410 roll at one time, 5 36 exposure lengths, notched and with a precut leader. That may have been diverted from the packing machine.
Some machines I have seen described do the perforations at the time of spooling, being fed a roll of unperforated 35mm wide film. LOok at the ADOX.DE you tube video of their perforating machine and see the big wheels on the lower right hand side where the numbers are put on, and the mention of it punching a hole where the film is to be cut.
https://www.youtube.com/watch?v=bo4piI1JaWA
220 would be nice if I had a 6x7 or 6x9 camera, more so than for my 6x6 and 6x4.5 ones. Closest work around is probably a camera with interchangeable backs and/or inserts that you can pre-load and swap quickly. My M645 Pro fills this bill; my Yashicamat 124 certainly doesn't.
Certainly an assistant to reload backs is a work around. I do have a Mamiya 645 with both 120 and 220 inserts, but I guess I will not get a chance to try the 220 inserts.
One thing working against 220 in B&W is that it cost quite a bit more than a pair of 120 rolls, and if you are doing the developing yourself there is little saving in processing. Even sending out colour to a lab, 220 cost more to handle as it would not work well in a plain dip and dunk machine as it would be a touch long. FIne in a roller transport machine but using twice the chemistry. so little saving in processing cost to again make up for the higher cost that two rolls of 120.
