I don't know if anyone else has found a "solution" yet, but I've seen the "problem" mentioned in several threads without comment... the $30 flippin' magnet for the M12 stick light. I couldn't see spending that on what seems to just be a plain old magnet for my $80 light, either. I finally found a much stronger, much cheaper solution.
http://www.amazon.com/gp/product/B00HVGK9S4/?tag=atomicindus08-20
<$10 for 2 of them, just add a 1/4-20x1/2" flathead screw.

Note: I've got no relation to that company or product, not pimping, just sharing.
Damn thing is almost too strong, stick it to a decent, flat steel surface and you have to yank it pretty good to remove it.