I have to actually try but I have actually overloaded my 803a with my house.
Clothes dryer, convection oven + a burner, electric hot water heater, furnace blower, 2 fridges and a deep freeze. (+ Normal house stuff)
I think that was around 90-110% load.
Turning on my 60 gallon stand up air compressor pushed it over the edge. Surge caused it to bog and spew smoke, turned off the oven + burner and she came right back.
I can't remember if the A/C was running or not.
Normal house load is around 15%.
Moral of the story is these sets can take alot but they do have their limits.
I could definitely make due with an 802a, would just need to manage the load, maybe put a soft start on the A/C.
But I got an 803a for one simple reason, I didn't want to worry about it.
My MEP gen has mainline monitoring, auto-start, switching between gen and mainline, auto-shutdown.
That means it can/has switched while I was away from the house, worrying about it overloading a 802a and bogging until it trips overload is not a stress I need in my life.
Sorry this post ran a bit long.