The case saver bosses can be broken by the case saver during a chain failure, and beefing the bosses up usually only leads to bigger holes in the case.
Sometimes when that happens the chain damages the shifter shaft as well.
What needs to be made is a frame mounted case saver that doesn't use the engine as a structural component during a chain failure.
It's easy to repair a steel frame, but repairing holes in the case or fixing bosses is a lot more involved.
Maybe something that attaches to the engine mounting bolts that doesn't require welding?