I’m sorry, I’m not quite sure what you’re asking to do here?
Are you trying to get the livery in question to be usable by you or by Air Traffic?
If you want it to be usable by you … isUserSelectable has to =1 .. 1 means yes, 0 means no.
If you don’t want it to be used as AI air traffic, isAirTraffic should =0.
But this only works if you have the “Use Generic Aircraft” = yes in your options under traffic. If it is off, then MSFS ignores everything and chooses whatever it wants for Air Traffic. So you end up with 20 Bleriot XI’s all over your airfield, or Spitfires or P-40’s dug into the ground, but none of the planes you actually want to show up as parked aircraft where you set the isAirTraffic = 1. sigh.