BuddyPress.org

With something that has the potential to, in effect, break a site layout, using client side scripting is never recommended as it doesn’t degrade gracefully, those with scripting off or blocked will suffer (granted that’s not many).

As I said one option is to remove indents after a certain level and perhaps instead colour code their backgrounds.

Better is that nested comments have a limit; isn’t that an option that WP has with threaded comments