Simply, kill the least recently selected tab, if number of tabs exceeds the configured value (could be by default say, 64 or so, in order to not baffle users who don't want this feature).
I usually work with the window split in two (cmd+opt+2), and the number of tabs grows quickly too large (say, over 15 tabs or so) and I can't see the ones I'm actually working with.
It'd be really nice if the least recently used were killed automatically, and the user could specify this number. It could default to 100 or so, so that users not wishing this feature would still see all the tabs (files) they have
Customer support service by UserEcho