Yes, I would not try to run an AC from an inverter. Period.
I have been trying to figure out a way to use a battery and possibly an inverter to absorb some of the surge for an AC startup but have not found a way to sync and the 12v DC connector on a typical generator/inverter is only rated for 10A.
OTOH the motor inertia in a generator allows it to absorb a millisecond surge and a 12v battery has A Lot of "inertia".
The major problem I ran into with the Predator was that its bigger and longer stroke engine (Westpro is 79 cc, Honda 98cc, Predator 125cc) does not rev fast enough to contain the surge. Did fine once the soft surge was added.
In fact the most cost effective combo is a Predator (on sale regularly for about $400), 2 year service contract: $79, Soft-start device: $300. I just personally like the Westy better.
I go into a lot more detail on my web site but the bottom line is that a 13,500 rooftop AC uses a cheap kludge to start that depends on electrical inertia (not right term but would need to go into boring math about phase angles and line capacitance to describe otherwise) for starting that is actually hard on both the system and the motor.
Big expensive rigs all have "soft start" devices that are just not cost effective for something sold at Camping World or Lowes. A few better ones stage the start so the compressor starts first and a few seconds later the fan(s). Most don't bother and rely on the fact that most circuit breakers can absorb a 300% overload for less than a second without popping. Still I would not try to run an AC on a 15A breaker, only on a circuit designed for at least 20 (I use 10ga wire in my garage).
ps Have run into a gadget called
5-2-1 and seems too good to be true. Anyone know if this is a gimmick or real ?