Audio Playback Package - with Schedules for volume

Would there be a way to use/modify the in store radio player package to accept a direct audio input and to be able to then output this but enable control over the output volume based on a schedule?

Some of this functionality is almost there in the existing In-Store Radio Player package but for particular use cases such as hospitality etc that already have an existing audio setup to playback music but require an automated method to set the volume at specific times/days this would be great.

Also, in the existing In-Store Radio package would there be a way to add a trigger option, maybe using a GPIO pin, that can be used to play the overlay file.

That won’t work: The Pi doesn’t have any audio input connector and external USB input isn’t supported.