VSCode extension (see marketplace) that highlights the cursors when there are more than one of them. (Using Atom? See the Atom package.)
I found myself forgetting the multi-cursor feature on, and editing multiple places by accident. So I wrote this package that annotates the cursor with the number of cursors. The extension is activated when the user creates multiple selections with e.g. cmd-d.
No settings for now.
I wasn't able to find a non-hacky method for adding "absolutely positioned" UI elements where the cursor is. The current method dictates a non-optimal placement for the badges, and it might cause a single character to jump a pixel or two horizontally. Also, the badge doesn't show properly when its cursors near the beginning of line.
If there are more than nine cursors, only * is shown in the badge. That's just laziness.