Yeah great day. Drove to work and CEL still on but drives normal. Called dealership and set up Tues appointment. Service manager asks about gas cap. Check, first trick in the book right.
Leave work and light no longer comes on. Wtf? Should I keep appointment or still bring it in for inspection? Will I get charged if nothing is found?
Man this car has its qwirks that's for sure.
Not screwing the gas cap in until it clicks is a common cause of a CEL. That isn't a quirk of the QX30, but rather of a standard fact of every modern vehicle.
Whether you're charged or not really depends on the dealer. Most shouldn't charge, imo, since they can see the code in history and will know you did have a valid complaint. However, there are bad dealers out there, too.
The code you posted is not the code I'd normally expect for a gas cap not sealing (typically P0457 for leak). It's possible it's a coincidence... Troubleshooting steps in the manual don't list the gas cap as a typical cause for P052E. It's possible the actuator became unstuck. It's frustrating not to know the definitive cause, but in situations like this the best you can do is keep an eye on it.
Personally, I'd wait until Monday afternoon and if the CEL or code have not come back, I'd cancel the appointment.