Honored guest or no, Jaskier would be very motivated to perform music during the festival (if it's all right for him still to have procured a medium-quality lute, as per my TDM question/answer) as he means to get his name out there one way or another... and it's a great way to schmooze with the locals. Would Thorne allow his performances and would there be any (potential) reward/payment for doing so (even a few tossed coins?) He'd want to perform either way.