How to manually edit ~/.config/kwinoutputconfig.json?

[deemon]

How can I edit the kwin output configuration manually, so it sticks?
I mean I can edit the file ~/.config/kwinoutputconfig.json all I want it never matters and on some point it gets overwritten with whatever was there before. Either if you go to GUI “Configure Display Settings…” and change anything there or just reboot or do whatever.

Tried to change the refresh rate for monitor there. Didn’t stick. Went back to previous settings.
Tried to change the refresh rate for disconnected monitor there. Didn’t stick. Went back to previous settings.
Tried to remove old monitor from the file that I am never going to use again. Can’t get rid of it and it keeps coming back to the file.
However every time I change anything in the “Configure Display Settings…”, it becomes permanent. THE PROBLEM is that I can’t change any settings for disconnected displays there (in the GUI). (some of which might be permanently destroyed and doesn’t exist anymore).

Almost like kwin is keeping it’s own configuration somewhere else entirely which it is using and out of courtesy to me, just occasionally copies a snapshot for my viewing to ~/.config/kwinoutputconfig.json, but never actually uses it itself?

So where is the “master” configuration I need to change?

[Aragorn]

You cannot make any changes to any of the Plasma configuration files by way of an editor while Plasma is running, because they’ll get overwritten again.

If you really want to go there — at the risk of breaking your system — then you have to log out of Plasma, log in at a tty, shut down sddm, edit the file(s), restart sddm, and log back into the GUI, in that order.