This is more of an issue for users navigating the site with a keyboard (Tab or Shift+Tab). At the very least, it affects all the checkboxes in the Workspaces view.

When a checkbox has focus, there is no visual indicator. So, you can use your keyboard for most of the interactive elements, but the moment focus shifts to the checkbox, it's not clear where you are, or what pressing Space/Enter will do.

Should hopefully be a straightforward fix. Only obvious pitfall to me is that you have to make sure focus styling is defined before hover styling or active styling in the CSS cascade