It seems like pressing 1-5, even on the numpad will not change costumes/emotes unless the window is currently active and on top. This is a bit counter-productive while streaming unfortunately. Is there a way to bypass or fix this?

I made something that can help you with that in HIDMacros and AutoHotKey (It's works fine, but It's kinda half-baked tho).  I'm currently making a video tutorial for it. Once I'm done making the vid, I'll probably make a new community post for ease of access. But in the meantime, here's the google doc folder that has the instructions and the files I made: https://drive.google.com/drive/folders/1ior8OpDd7Y8q55yAbyJuPc-F5dwEtbCU?usp=sha... the instructions are in the PDF in folder.  If you or anyone else has any questions, just reply below.