Well enough to be dangerous. I was able to get the JACK Daemon running on my Lenovo Laptop running Fedora 32, and us it to record MIDI-based music.
The steps were relatively straight forward. First I had to shut off Pulse Audio.
systemctl --user stop pulseaudio.service systemctl --user stop pulseaudio.socket
Specifically, the [>] referred to in that doc was no longer there, but the drop down had what I needed. I had to select the right audio device, which for me was HW:PCH
I went to QSynth and changed the Audio “Audio Driver: alsa” as well. And with that, I could record MIDI. Rosegarden automatically connected to the EWI. Switching between MIDI devices was done in QJackCtl’s graph dialog, just like I did before.
And, with everything set up this way, audio no longer worked for the video conferencing tools in my browser, so it is only temporary.