Doing the same for a House of Worship service. As you indicated changing scenes, as others indicted, why even have the microphone in the scene with pre-recorded video? My approach has been to remove the microphone from the scene when playing pre-recorded video snippets. Thanks to @
Warmuptill for being super responsive and fixing the initial bugs in the Media tab (fixed in 1.6.1). So my scenes are self-contained (either live video or pre-recorded... never both... learned the hard way after a few too many times of forgetting to mute, or unmute, the mic manually) play the video, and use this plug-in to auto-switch to next scene (with live video fed, and microphone present in audio source).
The only thing I'm missing is a PowerPoint page change (next) with scene change. I'm looking into combining the Dummy Source to execute command and python script PowerPoint slide window navigation using OBS hotkey 1.0, as I don't want to use (or have to remember to hit) hotkeys. In my case, I never have a scene change that doesn't also involve a PPTx slide change.