Kubuntu 20.04 - front panel audio jacks "unplugged" and Analog Stereo Duplex profile "unavailable"

This is really a workaround to make changes in pavucontrol GUI permanent rather than correct jacks appearing as "unplugged" and profiles as "unavailable". I thought I could share it in case someone bumps into similar problems and it is maybe too large for a comment.

PulseAudio has a command-line interface that is documented in man pulse-cli-syntax (which I found here). These commands may be tested in pacmd (which I found here). Using this documentation and pacmd's help, I found that the two commands I needed to reproduce my changes in pavucontrol are

set-card-profile 1 output:analog-stereo+input:analog-stereo
set-sink-port 0 analog-output-headphones

Then, to make these changes permanent, one can change ~/.config/pulse/default.pa (a list of related configuration files is shown in man pulse-cli-syntax). Here, I appended the following:

### Set Built-in Audio (HDA Intel) profile to Analog Stereo Duplex
set-card-profile 1 output:analog-stereo+input:analog-stereo

### Set Built-in Analog Stereo port to Headphones
set-sink-port 0 analog-output-headphones

Finally, pulseaudio -k restarts the sound server and confirms that these two changes apply. The same should happen at restart.