A remark about 'élingues' ('slings') caught my attention in the French video.... to be used to bring some of the larger parts to the surface.
The Remoras can only pick up small bits and pieces, not entire engines or big fuselage sections.
Unless the recorders are actually lying on the seabed ready to be picked up (unlikely, to say the least), they will either have to 'scratch around' in the tail section, and try to extract the recorders, or use 'slings' to lift the entire tail section, while hoping the recorders don't fall out halfway to the surface....
Said slings having to be put in place first remotely, at 4 km down, by little robots....
I wish them luck, lots of it, and no finger trouble......