Carrying a spare fixed blade prop is not a bad idea. My PSC 34 came with a spare fixed 2-blade I assumed was included from the factory (but I suppose it could have been from the prior owner).
I've done a lot of research on the Max Props and haven't come across anything like what you're describing, but I could see where it might be possible given the right set of circumstances. Are you sure you're not just a really unlucky person?
Despite the small risk, so many people have reported such long term reliability, I'd say the benefits far outweigh the risks overall. It's probably not a bad idea to practice taking off / putting on the Max Prop when people have their boat on the hard, just in case swapping in the spare is ever called for.