Biggest problem in high current is the reg, you may need to turn your head to breathe. I have felt the current tugging at the mask when we were anchored to the reef to watch the shark parade but never lost it.
If you want to secure it wear a beanie over the strap. Any line connecting the mask to the BC could become an issue. I have seen divers with full face mask carry an extra in case they need to bail. If you are really worried put your extra mask in a BC pocket.