I’m not sure I am up to the task. I think it would be a killer feature though. With so many mark-up types (html, xhtml, xml, rss, etc.) to would be a really cool to see where tags are closed.
It would be great when reading markup and would also prove invaluable when checking tags are closed correctly without running the CSE validator plug-in (nice plug-in by the way), or if you want to grab a node to copy and paste into another document.
Maybe an idea for a future release?
Keep up the good work! EmEditor isn’t just good to have, it is essential!