The main advantage of electric power is that it allows the ducted fans to operate in any attitude, up to and beyond vertical, which aids getting airborne. if this was required from the current car-derived diesel engines, re-certification may be necessary. Vectoring the fan has got to give more vertical thrust than the current vanes in the prop wash, however good they are.
The Airship Industries 500 and 600 used Porsche flat 6 engines which drove vectored, ducted fans. The engines were in-board, (in the rear section of the gondola) and each ducted fan swivelled around the drive shaft from its engine. So the engines themselves remained static and fixed.
I flew in one for a BBC outside broadcast where we provided a live top shot of a cricket match at Lords. We stayed right over the pitch for a couple of hours.