My true repair was to use a nut setter on the metal part of the door to decrease the flex of the thin thread engagement of the door sheet metal. That way once a fix like yours is in place or new ones installed the door strap can still be used. I once made a joke about the regal having the weakest door straps in existence. There was an 84 Olds door in the junkyard on the ground. I picked the door off the ground by the door handle and tried to throw it like the hammer throw, the door handle didn't break. Nice work on your repair.
You know I'am sure your right Nick but I never use the strap to close the door. Just the handle. I only threw in the washers just to make it tight. Before the washers it wouldn't run the screw all the way down. You now now that I think about I'll take your advise on the nutserts. An once of prevention is better than a pound of cure... (WOW I sound old)