When adding new buttons to the "Brushes and Stuff" or the "Main toolbar", some of them disappear next time krita starts up. For example, the "About KDE" button gets remembered after restart, but the "freehand path tool" doesn't. I'd like to add buttons from the "Tools" docker to "Brushes and stuff" like the transform tool or the rectangle select, but they disappear every time. 

The separation between "toolbars" and "dockers" is very confusing. The "Tools docker" on the left looks like a toolbar, but isn't. There are only two toolbars but they're both 100% configurable, so why not make it possible to add and configure as many toolbars as needed?

Reproducible: Always