For those who use imitation Glock 21 mags, I do not recommend RWB Korean or ETS G21mags (Lage said ETS functions on his upper). KCI Korean are better but OEM Glock mag/Kriss extensions are most reliable. I have not tested SGM or Magpull G21 mags. I learned the hard way that many after market Glock mags will not fit my CMMG 45 magwell. I do't know Richards magwell dimensions but it's something to think about.
This is the first time I've wanted a M10/45. The VERSA-10 upper with a ROF of 484/600 RPM would be really fun. The upper cost less than my CMMG 45 Banshee and SS.
My first MAC was a M10/45 with an original (all steel) Lage upper. It ran like a top. I have since sold that gun and upper (should have kept the upper). Every time I have tried a .45 ACP upper combined with M3 mags since I have not seen the reliability I would like. My original upper never malfunctioned unless it got really hot and burned off all the lube (I solved that with LSA grease). My only M10 now has an Uzi mag conversion. I only have one .45 upper for it, and I never use it because it is a stock style with a super high ROF. Even so, while Uzi mags are great for 9mm, they are not the way to go in .45 ACP.
So, I have some interest in a .45 ACP upper for my M10 with its own magwell. I have a bunch of M3 mags, so that would be the obvious choice. However, I also have a BRP-Stemple gun with all the .45 ACP parts. Getting a VERSA-10 for my M10 that uses M3 mags wouldn't really get me anything except the ability to shoot .45 ACP in another gun. So, my interest is in Glock mags. However, I'm unsure about the various extended capacity Glock 21 pattern mags. Most of them don't seem to have a good reputation, even the Kriss mags get mixed reviews. I have a B&T GHM45 SBR that uses an excellent magazine, but I doubt there would be enough interest in those for an adaptor.
Right now I'm on the list for a VERSA-12 with the Glock mag adapter. I'm still on the fence about the VERSA-10.