@moonshinebrigade @ubuntustudio Hey we use Kubuntu (KDE desktop environment and ubuntu) and Ardour in our band rehearsal room.
We have two audio interfaces connected together to get enough preamplified inputs and outputs. interfaces: Focusrite liquid saffire 56 pro and Scarlet 18i8. They're interconnected (I think we use ADAT or so for the connection).
IIRC only one of the interfaces (Scarlet) is connected to the pc.

@moonshinebrigade @ubuntustudio Sometimes there is some weird default configuration on the scarlet Interface (monitoring enabled on output channel one).
There's some open source GUI program for configuration of the interface (Edit: https://github.com/x42/scarlett-mixer).

We use ardour for our monitoring and for recording.
We are 7 people and have individual monitoring which means at least 10 inputs and 8 outputs (7 monitoring [headphones] + 1 master [speakers]).

@moonshinebrigade @ubuntustudio We use adapter cables to split 4 stereo headphone outputs into 8 mono outputs.

@moonshinebrigade @ubuntustudio To have individual control of the monitoring we use OSC (open stage control) which is a web server that essentially talks to ardour.
Everyone can change their monitoring on their smartphone.
More specifically we use the following configuration:
Each individual mix is implemented using a 'foldback bus'. The following repo has an OSC config file which allows full control over the individual mix. https://github.com/Sogolumbo/ardour-control/tree/master

@moonshinebrigade @ubuntustudio This setup works well for us but needed some fiddling around to get right.
There are bugs in ardour's OSC support (workaround: all tracks that are used in the monitoring have to be to the left of the remaining tracks).
Also we need to run and host OSC 7 times on 7 different ports to get independent control interfaces.