I've experience a similar baseplate failure before. Mine sheared near the heel like your's did.
FYI, I only use the long baseplates now. They are beefier around the toe and heel due to being longer overall and wider in the toe and heel areas.
The long baseplates are somewhat of a secret item. They were never available on the website store. Only available by request. I don't know if they have any in stock or are still making them at this point.
+1 for long baseplates! Jim, please keep making them for us big guys!!!