@guss77, that’s what was missing! Thank you, again.
For future reference, I utilised the undermentioned: [1]
I can now set my brightness (via ddcutil setvcp 10 $int), and the plasmoid’s slider is absent:
ddcutil setvcp 10 $int
superuser.com/revisions/1885525/3 ↩︎
superuser.com/revisions/1885525/3