I have a related issue.
1 select all does not have a corresponding action 'deselect all', either explicitly or by a second press of select all. Or does it?. This could be more important to anyone who has extended the scope of select all from displayed to loaded.
2 related possibly..... In the top menu, if you have already manually selected a single email in the left pane list, offers 'select list'. This seems to be functionally identical to select all. It is not visible if no item is already ticked. In this respect it is different from select all.
This item too has no 'reverse gear' - unselect list, that is.
I would like to understand how this is meant to be used and why no unselect?
Dave