the stream deck integration was only added as a way around background hotkeys before they were officially added. Now that there are real hotkeys just use those, they are much easier to set up.
Viewing post in Stream Deck integration not working
Just want to echo that this is the case for me as well! Since I use the same keyboard sometimes to type messages in chat, the use of modifiers for hotkeys would make sure my model sprites don't glitch out while I'm typing (e.g. if my mic fails or something) -- also not sure what buttons I'm pressing to make it happen but sometimes my model's face disappears when I'm typing normally (in testing) and I have to reload model to get it back
All this to say, I'm super happy with PNGtuber+ currently with the physics and costumes giving me a lot of beautiful creative reign as an artist; modifiers for hotkeys would be amazeballs cherry on top ✨👍