Authors should not be allowed to change styling
Authors should not be allowed to change the applied styles at any point during the editing workflow.
Production editors and copyeditors should both be able to apply styling, as they can now. The production editor has primary responsibility for styling, and the copyeditor often will alter some styling as well. There is no need to track styling changes.
The problem is that if the authors are allowed to change the styling, it happens in an untracked, silent way, and editors have to recheck all the styling to be sure it hasn't changed.
The authors should still be able to click text and see how a block is styled, by having the applied style name increase font weight on the left-hand style menu.