We seem to be getting somewhere.
Since the Y ELEC PUMP is supplied by AC2 and DC2 (FCOM 1.29.30 p1) it is not available in DUAL ENG FAIL unless we start the APU (which seems pretty sensible, in my opinion. Besides, even in the old models the flight on bats only is just a transient situation, after a go around before pushing the button and restoring EMER GEN).
The other question remains: Is the Y ELEC PMP able to move the flaps, given that it is less powerful than the Y EDP?
I think they should at least write a note explaining why the Y EDP cannot be used, or if it can be considered.
And another question: Is there an ideal configuration in case of a ditching or a forced landing, or the more the better?