When it is hotter than Hadies in August,,, you have little choice but to run the Generator to run the A/C to keep.. well as cool as possible.
I would not worry about running it too much, The ONAN generators are designed to run run run for long and I mean LONG periods of time, 10-16 hours a day is not uncommon in some installs for those puppies.
In fact, The concern you should have is not running it enough
Run it at least 1/2 hour under 1/2 load the first of every month.
Home is where I park it!