Nope, magnetization is like bad taste, you can pick it up by just being in the vicinity.

I imagine that any ferrous object near a speaker magnet is going to get magnetized pretty quickly. I'm pretty sure the Allen screw is the one you are supposed to use for mounting, at least that's what all the threads indicate.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8