Hey,
in iOS 15 Beta there was an even worse bug, where you could not change the PencilKit Tool programatically. It was fixed in the final release.
I have also sent a bug report and it says: potential fix with iOS 16.
I am confident that this will be fixed in the final version, so don't worry.
If you want some feedback you can use your Technical Support Incident (TSI) and request some insight, which I did back in the days for the other bug.
Topic:
App & System Services
SubTopic:
Core OS
Tags: