I really appreciate this add-on. I think it is a wonderful set of tools for any presenters. (With face-to-face instruction back in this part of the world, I find the QR code generator really helpful (although generating a QR code can be done relatively easily on Chrome itself these days.))
There are a few limitations, but they result from Google Slide itself (i.e., they are known issues), NOT from the add-on.
I look forward to future updates and improvements! Thank you very much for the great add-on! Keep up the good work!