The transfer switch and inverter are dedicated to the refrigerator.
If you want to install a gas or diesel generator, you'll need to figure out a safe place for a fuel cell and sort out the fuel plumbing on your own. It's been discussed before, for a Bighorn I think, but I don't know that anyone has actually done it.
You'll also have to decide how to route the power. On factory generator installs, there's a 50 amp automatic transfer switch. Shore power and generator power go in one end and the other end goes to the circuit breaker panel. The factory usually uses a
Progressive Industries PD52. Another possibility if the generator has a 50 amp 240V receptacle is to plug the RV shore power cord into it when you are going to run the generator.
Exhaust routing is another safety consideration; especially if the generator is near the bedroom.