Multi AUX in and low latency through

I am a musician and a composer. I user high quality active monitors in my studio setup.
Whenever a pair of monitor boxes gets old or outdated, this pair ends up as PC speakers un office or desktop settings of my house an family.
Now I have two or three requests to the M2P developers.

Local AUX Play through
When having Raspberry PI connected to the pair of active boxes near a PC I cannot manage to add the „local“ M2P to use as PC Speakers. Using AirPlay leads to massive sync delays to PC Video. So YouTube Playing is impossible. I did not manage it to use a SqueezeBox Stream Channel as a PC Audio Out (like the bluetooth setting) to avoid the delay to local video.

So I request to have a simple USB Audio Adapter with Audio In connected to a local M2P Instance an then direct OUT to the local DAC. This setting should be possible within the „non-feelable“ 10-20ms overall latency.

Auto-Switch integration with ShairPlay Squeezebox auto-switch should be possible..Whenever local aux in arises a certain input value, then Auto-Switch selects Local-AUX-Thru as input source.

Multi-Room AUX Play throughput
Due to my musician and studio history there are turntables tapedecks and tabemachines in 2 of the rooms. I would like to bind one or more of the local usb AUX-In Channels (if multiple) not to local-through but to a certain squeezebox server channel so that I can do multi-room playing of a good old turntable Vinyl-Setting or can even do „scrathing and DJing“ for the family in multi-rooms.

Any ideas on how to get this running….