Is there a way to hide the key signature indicator (lower arrow in image) and the bar number indicator (upper arrow)? The coloured background of the key signature indicator covers an expression text partly. When the text is completely covered it cannot be selected anymore. I tried all possible options as well as the manual but don’t seem to find it.
The “bar number indicator” is the system track - see hiding/showing it here.
The “key signature indicator” is a signpost - see hiding/showing signposts here.
You can also select items behind other items (including signposts) by Shift-Alt/Opt-clicking them.
You can turn off signposts under the View > Signposts menu.
As well as the buttons for clicking items that Lillie has pointed out, you can use the ‘Preview’ key press to hide the signposts and select the text while you’re holding it.