There are school portrait cameras that take long rolls of unperf, and use the whole frame.
In 35mm cameras, you can knock the teeth off one with a thumbnail winding wheel (i.e. Oly Trip or disposable), but you won't be making use of the extra width.
I've respooled to feed my 828, but optics are "budget" and certainly inferior to your Rolleiflex.
Kodak made inserts for mounting 828 spools in 120 roll film cameras, and I have a set and they work.
126 and 127 respooling also options & will use the full width, if you find cameras with decent optics & manual controls.
I think your Rolleiflex is probably your best option, will use the film full-frame (35x60mm), have the best optics and manual controls. I'm not sure why your test roll wasn't held properly by your pressure plate, but you could give it another go.