Magnetic holders won't always hold your mag in the orientation you want. They can spin the mag on the belt leaving you grabbing the wrong end if you take off in a serious run
I willing to bet that already has a gunsmith fit fire control. Shoot it first. And know that the dremel can ruin parts much quicker than a stone or file!
Push the dimples flat! Check your follower, you might be able to relieve the contact area on the bottom to make it seat easier but not accept that dangerous 11th round.
Tritium is radioactive and regulated by big brother. The only way is to buy a sight with it installed... Or pry the vial out and get crackin' DIY style