I guess the only solution would be a thinner back plate... But I want to make sure that it would work before getting that part. There's also a contoured remote switch available, but because of the adapter the M6X is lower than it should be, so I'm not sure the contour would fit properly...I had a similar problem using GG&G's original rail adaptor (which was almost identical to the ProMag) with a picatinny BLAST-2 on my old USP45. I also tried doing a little dremmel work, but what actually ended up working very well was using a thin black zip-tie length-wise around the unit and the rail. It wasn't quickly removable, but it was very solid and it looked just fine.
WoW! Nice clean job! Tempting...I had the original GG&G and it stunk. So I did this to my USP... Not suggesting you do it, but it worked great for me.
BTW Botach can't ship to Canada... I just tried to order the rocker backplate and when the order was completed the "live help" sales person who told me they could ship it, told me the intl rep said that they couldn't.