I hid vector pattern fill (unfinished) by adding a bool property (visible: false) to the respective ui file.
This is intended to prevent Krita users by mistaking the unfinished feature for a bug.
The visible property can no longer be added in newer QtCreator/Designer versions.
The setVisible(bool) function also seems to be disabled.
To remove/add the visible property, please remove the respective lines in a regular text-editor.