I read through countless of threads about routing but couldn't find an answer, so hopefully someone here has one for me. I notised in several worlds that not everyone use the blue routing paint under the trees. I've always used it but is it really necessary? Most of the times the routing is fine around the trees but sometimes the round routing nodes are inside the tree's red footprint or half inside of it. If I don't use the paint, will those random nodes cause problems for the simmies? Will they get stuck on them?

No, those examples are absolutely fine, no need to use any blue non-routable paint there. You can see the red square which is the area the tree is blocking. And the routing runs ok around.

Okay, thank you so much answering. I think I'm going to remove the rest of the paint I already placed on some of the trees. Thank you again.