Hard to say with a new-2-you bike. If it's not up to snuff compared to the other kdx you mention, guess it's time to do some sleuthing.
Just cuz he has receipts doesn't mean anything was done right. I can count the number of times on one hand that 'someone else' has done something RIGHT on my stuff when I took it to be 'fixed'. Conversely, I CAN'T count the number of times it's been otherwise.
After I take it to be 'fixed', I take it home and 'repair' it myself. Pretty much got into fixing everything myself.
Do some simple stuff. Air cleaner condition? Clean it anyway. Maybe his idea of 'oiling' it was to soak it to dripping wet.
Even simple stuff like, is the carb opening all the way? Check the KIPS ops as a matter of course.
Jetting is almost certainly wrong. It most always is.
Put in a new plug. Change the oil (not related, but..why not?).
Bunches of 'stuff'.
Will give you some time to 'get acquainted' with your new scoot!
have fun