It would be great to have the last and average processing time in the tooltip (ports on the right) for each node.
This would help to identify which node slows down performance of the composition.
Opened for voting.
Just added my votes for this.
Not necessarily for the method proposed but because I often find myself wondering what parts of a composition I should be exploring if I want to improve performance.
I think the performance metrics should be something enabled/disabled so as to not in themselves cause an overhead.