I worked on unmanned ground vehicles that did this... 10 years ago. In fact we designed them from scratch. FWIW, now you have all the same joys of engine maintenance that one has with a traditional ICE car: oil changes, oil filter changes, spark plug replacement, starter replacement, coolant, probably an alternator, etc, along with needing to worry about an IG bolted on to the side of the engine connected to an MV bu…
I have a PHEV where the engine has about a thousand hours on it my previous car driven about the same would have had about three thousand hours on it. But there are definitely plenty of reports of people who have the plugging hybrids who never actually plug it in it so don't see this advantage.