Advanced Style Properties: Disable "<Reset to Template" if "Template" blank
Select Staff Properties > Advanced Style properties. If you press "Reset to Template," without selecting an option from the "Template" list, the staff is apparently reset to standard. This seems to makes no difference to standard staves, AFAIK, but it does mess up percussion staves (accidentals can even appear) and tablature.
Suggestion: The "Reset to Template" button should be disabled unless a selection is made in "Template."