Unfortunately yes... I'm using some of the latest SwiftUI API's to build the UI that I haven't back-ported for Catalina just yet.
Of course my work laptop is also locked on Catalina, so I kind of played myself there as well! I'll definitely consider adding that backwards compatibility in the future if possible.
I'm speculating here, but maybe there are better controls in Big Sur to easily mute input devices compared to prior versions of OSX. I've attempted building a global microphone mute app (for external microphones) on Catalina but never found an easy way to fully mute all mics such as external USB mics or a those connected through a USB ADC. The best I could get on Catalina was to lower the inputVolume to 0 which does not truly mute the microphone. I never found an app that "solved" this problem for all microphones on OSX versions prior to Big Sur.
That's definitely a bummer. On my work laptop I'm stuck on Catalina for the foreseeable future, and that's where this app would be useful. Presumably most people using macs for work aren't on Big Sur yet.
Huge bummer. It would be nice though if the FAQ included a short technical explanation for this limitation, similar to how it explains "Why does Unclack need Accessibility access?".
