The musescore way to visually remove a plugin 'panel' seems to be to click on a 'three-dots' button to the right of the plugin panel title, and select 'close'. However, for the fretboard plugin, this button doesn't initially appear.
What works for me is as follows: 1) double-click on the panel title bar. This makes the panel movable. 2) double-click again on the panel title bar. This fixes the panel in its current position. Now the 'three-dots' button does appear.
The musescore way to visually remove a plugin 'panel' seems to be to click on a 'three-dots' button to the right of the plugin panel title, and select 'close'. However, for the fretboard plugin, this button doesn't initially appear.
What works for me is as follows: 1) double-click on the panel title bar. This makes the panel movable. 2) double-click again on the panel title bar. This fixes the panel in its current position. Now the 'three-dots' button does appear.