I just used the duplicate mechanism which is built-in in UserEcho. Mohanarun's request is there in the original form under "duplicates".

How about this suggestion as a (partial, but nonetheless) solution to the problem you describe?
http://roadmap.cintanotes.com/topic/23145-forwardbackward-navigation-filter-history/

It's settled then ;)

Not clear what is necessary to implement and how it is different from what is already available.

Alt+BkSp is generally reserved as a doppelganger of Ctrl+Z. As soon as Undo is implemented, Alt+BkSp will be used for undo, as well as Ctrl+Z of course.