further more (in very simplistic terms!) an existing automatically deployed ELT unit could be fitted with an "SD card" which is fed data from the FD/CVR pair in real time. the unit would be charged, and the data fed to it, via an inductive loop, obviating physical electrical connections to the aircraft's systems.
FWIW the latest round of Micro SD cards (about half the size of a stamp) have now hit 128 GB.
That's enough for quite a lot of data storage, even plenty of room for recording video if you built a storage rack for a series of them about the size of a box of matches.