And here I come...
The low down. Tripp makes a .40/10mm system mag that he markets as for the 1911s with big magwells. They are cut down 10 round mags made to still fit the box but add length so that you can seat them in those magwell since he doesn't make an extended base pad for his mags. Now he markets them as 9 rounders. If your gun is well tuned they will hold 10 rounds, or at least mine did. They aren't on his website but if you call him he'll make them for you. Now like I said he doesn't market them as holding 10 rounders so they may or may not work. I have a couple 9mm 1911s so I just kept on shooting those with 10 round mags.
Will the "true" 10 rounders fit the box, I doubt it. The cut down 10 round .40 mags barely fit and I don't see how leaving extra room on there would but I don't own any "true" 10 round mags as I shoot L10 with 8 round SS or my limited gun.
Side note, if you have a 9mm take the wilson ETMs and take off that base pad and add a regular wilson pad and your golden.
I have been using Tripp 9 round and 10 round 10mm mags for .40 loaded long in my Single stack .40 for years. The 9 rounders for ESP in IDPA and the 10 rounders for L10. The 10 round mags are to long to fit in the box. I recently purchased an Ice magwell for my gun and the 9 rounders were just a bit short to seat positively. So I called Virgil and ordered 4 System mags, I received them 10 days later. Mine all hold and run with 10 and the gun fits in the box no problem with an 1/8 inch to spare (bomar rear sight).
It sounds like I need to give Virgil a call.