All of this talk of tracking and ejectable recorders seems to me to be waste of time and money.
Failure to recover the recorders is extremely rare, MH370 is a one-off event.
Finding the recorders in a few days rather than a few weeks is not going to affect safety or save lives.
The probability of finding survivors following a crash at sea is very low and in such cases we would expect to find EPIRB transmisssions anyway so what exactly would be gained by such changes ?