Thanks, everyone, for your input. As I suspected, there's really no good reason to have an external generator. FWIW, I have 600W solar, 4 LiPo batteries (400Ah), and no, I don't really want to have to store gas for the genny onboard... yes, I agree it's a hassle, that was one reason I posed the question... and I, too, typically run my onboard generator when using a high Amp appliance.
As for the consequences to the external genny, I don't know why it didn't function properly after charging my battery bank... it would start and run briefly, then shut down. Can't tell you if time has healed it, for it belonged to someone else, and he used his all the time for his setup (pull behind trailer, no onboard genny)... thankfully, he had two.
I'll save the external genny for power outages at home...
