They key is VLP. Very light pressure. You have to just barely “bump” it next to the platen. I’m not sure how tight of a radius one can achieve using the jig method as above. I guess it all depends on how small of a small wheel the jig will accept.
Hey, have you tried letting the belt overhang the platen or wheel just a tad…. 1/8-1/4”.? I’m not sure if plunges like this are what you’re looking for, but it’s a lot faster… no tools necessary.