^ This.

Pulseaudio should not even be involved, as the program do not require it. But then it keeps inserting itself into the "conversation" by hijacking any connection to and from Alsa...

Do you use an audio interface? What have you found is supported well by Linux? Saffire Pro 24 + Addictive Drums + Logic is what is really keeping me tied to macOS at home.

apt remove pulseaudio pulseaudio-utils then reboot, not really that hard.

Tame the beast with Cadence: http://kxstudio.linuxaudio.org/Applications:Cadence

This control panel app includes support for a PulseAudio-to-JACK bridge, which makes (if I remember correctly) PulseAudio a wireable source and sink in the connection graph while the server is running.