Thanks everyone for your input
Please excuse my poor choice of scooter terminology...
I have already trialed-and-errored most of these suggestions -- used the Techron, fuel injector, adjusted the idle, opened the gas cap for ventilation, etc. It's ridiculous that I have to use these work-arounds. But yes, this problem happens most often after I fuel up or after I've taken it off the stand and am about ready to roll out. I do have a bad habit of revving the engine as soon as it starts up, so I'll try and practice my patience (starting tomorrow).
So is this just how it is.. and I have to learn to deal with it? Or is it a defect that I need to bring to the attention of the shop I bought it from?
Has anyone been able to mickey-mouse the emissions sensor?