Just an idea, might be useful...
I think it would be nice to have an option somewhere, maybe in System Settings | FlightModeSettings, that allows once FC enters Auto Land mode - no matter via FMS or as a post-command of RTB - to continue the autolanding sequence until its end, then disarm!, no matter if FailSafe is triggered meanwhile. This will help to save the vehicle in case of emergency landing when the battery cannot last enough for RTB (presumably set as FailSafe mode) and the vehicle is far enough from Radio Transmitter or there are near-ground obstacles in-between that will cause loss of radio control and video contact before the auto-landing completes.
Although it's risky to leave the vehicle fly in the last moments without direct pilot control, I think it's better to auto-land blindly at 0.6-1m/s vertical speed than to drop uncontrollably at much higher speed from sky somewhere else with depleted battery, desperately and hopelessly trying to RTB.
What do you think?