I "had" the iseb and 15k AC and had no issues, but in Econ mode it sometimes would seem like AC compressor was kicking on slow. I installed hard start cap and it never gripped again.
I normally keep fan running as I like the circulating air. That also takes the fan motor starting amps off the genny during startup. Only the fan running amps are present which are normally pretty low.
With th is model I'm sure you won't have an issue with the is in non-Econ mode, but in Econ mode maybe.
My thoughts are the hard start cap should be used anytime a genny is used just to help out the AC. Low voltage will kill a compressor motor fast.
My new unit has a 15k and a 13k so I now have a honda 6500is and still installed hard starts on both AC's. Only reason for the move from yamaha to honda was I can take wheels off honda to make it shorter. With wheels removed it sits low enough in front of my hitch to not hit 5er front cap on tight turns.