While some FES equipped true gliders can self launch given a
long enough runway (and ignoring various legal factors) this
leaves the batteries depleted so there is no real retrieve
capacity remaining.
The only realistic self launch/FES mix is the Silent Electro at
13.5m so it isn't the answer to the original question.
My understanding is that Lange Aviation (Antares 20/23E)
don't see an electric (turbo) option (FES or otherwise) as a
realistic product. Their Solo engined Antares 18T should allow
pilots to retrieve from the wrong end of a failed 750K + flight.
To achieve electric long range retrieve needs very large
batteries; back to Antares 20E size, weight and cost.

Not sure I agree with their view; I think FES is a good product;
future sales will tell the story

Self launchers are another matter and perhaps best not mixed
with a FES discussion?