A lot of bad things and a lot of good things would have to happen at the same time in order for these to be useful and actually get used.
I think I have read every RV incident report, and a lot of other GA incident reports and I'm struggling to recall one where something like this, even if deployed correctly and in time would have changed the outcome.
Our flying club had an incident where a capacitor in the cabin failed, filled the cabin with smoke, and of course scared the **** out of the pilot. She wisely landed the aircraft in a field, about a mile from the airport, not knowing the cause or eventual extent of the fire or if she would be able to maintain control long enough to get to the runway. Minimal damage to the aircraft and humans.
What conditions were you thinking of that might be helped by these devices?