Anything on saddle itself in case of bridge break?. Low percentage I know, but certainly will call me.If there isn't already one on your tether, tie a figure 8 on a bight on the tag end. Bring that up and clip it into your biner on your bridge.
True, and d-ring would have been perfectThis has been visited a couple of times. There are different ways to accomplish a backup here (my suggestion for NT was to do a waist buckle with a load rated d ring).
The thing you have to remember here, is that you still have single point of failure at your tether to tree connection. You can back up your bridge and bridge connections, but it still goes back to that single point of failure - your true odds of something going south really don't change much.