[TomTom]

These difficult navigations I find fun, but often do them in isolated tests first before proceeding to the full project (northpole had at least 4 special cases to do before committing to finish the waypoint). The use of the prone flag via actions is not ideal but in Northpole I was able to use it via an Alt-roam inside the cannon. That worked because the cannon was a longer path so the bots really only accessed the cannon by the route system. In your case the sewer is the natural shorter path so bots will chose it in ways you can not control by routing to an alt-roam. I guess the teleport is the best way, though if you get the bots to crouch you might shift its trigger point to inside the sewer.

I agree that nodes should also have independently a crouch and prone flag to handle a few special cases like keeping under cover. I added in the wiki's FritzBuglist_ET a requested:new functionality sub-section for ideas like this. If you have a well thought out case feel free to add something on new behavior flags for navigation nodes. Bobots as I recall used different types of connection wires for some of its bots behavior.