In case anyone wants to use something while waiting on some features for this, here’s an alternative set up:

Cheap Ikea ZigBee smart plug and an analog Bluetooth speaker(s) (like the Marshall ones) kept at on with volume set to max (and, if using a music player that supports it on your phone, you can keep bass and treble controls at max as well).

You can then turn on the smart plug, which will turn on the whole set up, connect your phone via Bluetooth, and play the music via a file manager that has a music organizer (if music is on your own server) and control volume levels and an equalizer on an app of your choosing.

At least, that’s how I have things at the moment