This case mildly annoys me:
I have a Q&A open. I see there are hidden comments under a post and want to expand them using the keyboard shortcuts. That is achievable by pressing C.
Here is how the help information (pressing ?) describes this action:
C add/show comments
The problem is that this expands the comments and opens up the form to add a comment. Thus the focus shifts to the text box, so I cannot use any further keyboard shortcuts - instead, I just type them as a comment. My current workaround is to press Tab to switch the focus over away from the text box and this be able to keep interacting with the page via shortcuts.
This is a divergence in behaviour when using a mouse and the keyboard shortcuts, which makes the latter more irritating.
I would like the ability to only show the comments without automatically trying to add another one like we can currently do when not using keyboard shortcuts.