No!

The lastnode_id isn't intended just for that... someone as smart as vroom wouldn't be jamming all the links with that param, so that you know what's the current node you're in... AFAIK, it's intended to keep track of the navigation flow inside the website..

This is used for keeping track of how the user goes from node to node, and then the webmaster can fix the navigation system, based on the data he about how users navigate.

No! this should stay...