There is no added safety with new recorders or continuous transmission , the only difference being that it may be found by now and a story about what happened, although nice to know still resulted in the deaths of 239 people.
If you picked up a live hijacking and shot down the aircraft then the result is the same as the ocean crash.
All aircraft boxes need CIrcuit breakers to protect wiring and prevent fires , they can all be turned off and that cannot change.