Yeah, was hoping I could even like... double adapter it, haha. I tried to use normal adapters, but the M5/M6 issue is what is ruining it for me. That's obnoxious.
The IS mounts and adapters use bigger bolts than the L-Twoo calipers have space for, so it seems like it's just gonna be a mismatch.
Time to return the whole freaking groupo.