encountered a problem when using plasmovoice, I use not expensive bluethooth headphones from JBL that have a widespread problem with Stereo mode and microphone usage. When playing minecraft with plasmovoice I just can't listen to anything in stereo mode because game using my microphone. Adding a “Not Selected” option for turning off microphone/headphone using would help a lot.

It's already possible to disable microphone, but it's not really convenient.
Change voice.disable_input_device to true in the config config/plasmovoice/client.toml.

I'll think about more convenient way to do that. I don't really like the idea of selecting "Not Selected" device, it feels odd.
Most likely I'll just make an option to disable microphone / headset in the Advanced tab menu.