I know we had a poll some time ago and decided that we'd live with mirrored ROYAL MARINE badges on the arms....
I just came across this and was wondering if this could be used to avoid the problem:

The idea would be to have it "right way around" on the right (clan=squad.xml thing which we're avoiding for now) and then use a custom insignia with the "right way around" patch/badge for the left arm.
(I.e. make it so that the insignia covers the "mirrored" one).
This might not be feasible or simply not worth it but I randomly came across this while looking for something totally different and thought of this....