It would be nice to talk about hardware implications in this setup. My assumption is any class-compliant multi-IO interface should work fine in FreeBSD but I have never taken the time to look into myself. I have done a lot of Audio work in the Linux world in the past and it was always a hassle to get the right JACK + ALSA configuration so I could do multi-track recording.
I can’t speak to FreeBSD, but on Linux a lot of work is put into various generic(usb is what I’m mainly thinking these days) drivers to implement work workarounds for the never ending list of buggy devices that don’t actually comply with various specs. I learned the hard way when the audio interface I bought was so new that it wouldn’t work at all until some things were fixed in the kernel driver.
I don’t do audio work for a living but lately I’ve had mostly good experiences with PipeWire. My setup is fairly esoteric in terms of odd sinks/sources spread across multiple machines, but overall it has worked well.
Admittedly I’ve not done any recording in the traditional sense, just using it as a giant goofy mixer for having all my computers use a single microphone and headset.