A sketch of how to search session logs for funnel alignment.
It creates a rose tree composed of all the funnels of interest, and then each session gets matched against the rose tree to find complete and partial funnel matches.
The primary way that a rose tree is a mismatch for the problem is that sessions are allowed to include pages in between funnel steps without interrupting the funnel match. This means that instead of a simple tree search, it is necessary to keep a fringe of reached nodes in the tree and process search steps against the entire fringe.