I would be fine doing something like that with my hookup if my 60A DC Current output was not loaded down too much charging the batteries... The worse case situation would be it would take longer to charge the batteries if the frig was pulling down on the load too much... Once the batteries get past my initial high DC Current period and start tapering back as the batteries are taking on charge I would have alot of extra DC Current I could use somewhere else at the same time...
I do know my battery bank really draws alot of DC current when they are first hit with 14.4DC charging voltage then as the batteries start taking on charge it starts tapering back after being charged for 15-20 minutes.
Roy Ken