Didn't know how much applied to the M122.
Much of it in theory. As far as changing to an ANSI style Enter and other keys such as Left Shift, it is trivial when doing a bolt mod but impossible otherwise.
As far as programming, if you bought a cable from Orihalcon, he can answer directly the similarities and differences compared to Soarer's original.
I did buy a cable from Orihalcon, and it's working great. The left shift mod should be easy. The key next to shift, I can rotate the spring with pliers till it comes out and just drop a standard shift key in there. I've pulled springs out before with no adverse effect. The Enter, I think I am going to just have to get used to. I'm not willing to try a bolt mod right now. Perhaps one day when I find a Model M in rough shape that I score for $10, I'll take the time to try it.
My biggest problem seems to be hitting the function keys on the left by accident. Part of that is just muscle memory. On a regular model M, my pinky rests on the edge of the keyboard, since I touch type, and I guess I am used to the modifier keys being close to the edge.