Hello
Very new beginner on Arch, and also recently started using the Mate desktop. Not sure if either of these things are relevant, but am puzzling about why the kritarc file would alter itself ... I'd adapted the setting for the pop-up wheel, after having seen a Reddit post detailing how to change the numFavoritePresets number from 30 (I changed it to 34). Never happened before, in over 2 years on Linux/Krita, but soon after opening Krita, the wheel will revert to 30 brushes. A bit concerned what is changing the kritarc setting. I've changed the permissions for the file, with access only to myself, just now, but not sure if there's something else overriding things.

The kritarc file didn't alter itself, it was altered by krita, since it's krita's memory of settings/configuration. You can change all sorts of things by editing the contents of the kritarc file (before you run krita) but the best way to change the number of popup palette presets is to go to Settings -> Configure Krita -> General -> Miscellaneous tab and adjust Number of Palette Presets there then press OK.
That new setting will be stored, by krita when it closes, in the kritarc file so that it can remember it for you.

Well, 30 is the maximum, so when setting it higher krita will correct the value to be within limits.
Looking at the git history, the way brush preset icons are positioned changed in march 2019:
https://phabricator.kde.org/D19597

So that probably is a hard limit now, *maybe* you could squeeze in 2 or 4 more before breaking the algorithm, but I assume there is a reason why you can't bypass the limit by manipulating the kritarc file.

Hi and thanks for responses and advice ... I can see that the setting won't go beyond 30 within Krita, but I'd previously been able to alter kritarc, and the number hadn't reverted (lucky, lol?). I remember the palette changes; great to be able to fit more onto the wheel. It was actually after that that I'd made the changes, after seeing Boud say how to do it, in a Reddit post in July, so I can only think a setting must have been recently changed. It had been working really well with the 34 brushes for all this time.