I can't see where those bearings experience really that much load. I don't think their loading puts them anywhere near their L90 calculation.

They die from water and dirt.

I think I have thought up of a way to load them down with a bigger supply of grease and protect them from any water and dirt on their backside, while still maintaining their ability to be removed and replaced and without any machining. I will post the procedure when I actually do it.