Just to remember, every time this process a bit “stupid”. Short note, whole process from the begininng takes about 30 minutes.

• trizen -S colord xiccd displaycal xdg-user-dir # install necessary pkgs, xiccd for AUR
• run (temporary) xiccd -e -d :0 in terminal
• run displaycal interactive and complete calibration + profiling (Temp 6500K, Gamma 2.2, Brightness 90-120cd)
• peform some additional steps on boot/autologin, i’m using .xinitrc and “console” Display Manager (tricky but very lightweight):

        sh -c "pgrep -x xiccd > /dev/null || ( xiccd -d :0 )" &
        sh -c "sleep 5 && dispwin -L" &

Results:

$ darktable-cmstest
darktable-cmstest version 4.0.0
this executable was built with colord support enabled
darktable itself was built with colord support enabled

primary CRTC is at CRTC 0
CRTC for screen 0 CRTC 1 has no mode or no output, skipping
CRTC for screen 0 CRTC 2 has no mode or no output, skipping
CRTC for screen 0 CRTC 3 has no mode or no output, skipping

DP1     the X atom and colord returned the same profile
        X atom: _ICC_PROFILE (969380 bytes)
                description: PL2792UH #1 2022-08-04 21-57 2.2 F-S XYZLUT+MTX
        colord: "/home/ilyxa/.local/share/icc/PL2792UH #1 2022-08-04 21-57 2.2 F-S XYZLUT+MTX.icc"
                description: PL2792UH #1 2022-08-04 21-57 2.2 F-S XYZLUT+MTX

Your system seems to be correctly configured

Did it.