When AC draws huge amps for compressor starting, I measured 13.5k BTU to run on 6.2 amp and 15k on 8.6 amp.
Meaning once the AC is running, you don't have to worry about power spike till it would restart. Trick is to set thermostat very low and turn AC off manually, so it will not restart without your knowledge.
What size of inverter/charger do you have?
With proper size it is very easy- plug inverter into generator and start the AC on inverter power, once AC runs, start the generator and inverter should automatically switch to generator power, when at this point AC will draw low amperage.
Advanced inverter/charger will dose the available current between AC and charger.
