"beeves" - I like that. That's better than beefuses...I'll stop using that term.
220 Agfa sample I grabbed (no reason it would be any different) was WAY too wide to fit 2-1/4x3-1/4 holder, eyeball 3-4 mm too wide. I suppose two cuts aren't much worse than 1 if you have a sharp tool.
I bought some recently outdated 4x5 Ektachrome 64 on eBay to play with (cause I can't afford to play with the fresh stuff), and considered it to cut down too. I have 2 rolls of Agfa 160 in 220 left; I finally learned to stop trying to plug light leaks in 120 cameras. It was fun while it lasted in a Moskva V with the 6x6 mask further masked down to 645...got about 27 exposures hand counting turns, just too many leaks.
Next question is whether a lab can handle 2x3 color without clogging the machine...is this where a so-called 'dip & dunk' lab is desirable? I don't know exactly what's meant by that.
I found no color in the list of various brands at J&C, which was where I thought it might turn up, if anywhere.