Just had a thought of the most useful thing about gas/electric hybrid aircraft motors: if (for piston aircraft: when) the gas engine dies, you at least have partial power until you run out of battery. Potentially enough to get you to a safe(r) landing spot.

That changes the calculus more in favor of hybrid-electric. Probably still not worth the weight, complexity, and financial penalties you’ll be taking on with that. Like, I still wouldn’t do this for my rv-9.