That's dumb as fuck. The five times I've broken my thumbs skiing, I wasn't even using pole straps. Changing your pole straps isn't going to do shit.
There aren't many real solutions to this problem. You could either wear a thumb splint every time you ski, duct tape your hands so that you can't open them when you're falling, or try to land all jumps switch.
I think the splint thing is the easiest and most reasonable solution.