How can I make spline mesh with custom nav area?

I’m using Spline Mesh Component for my Road. And I also have Sidewalk for my game. I want to apply different nav area class for each of them. Roads should be placed in runtime but I found that Spline Mesh’s “Is Dynamic Obstacle” option doesn’t work well actually. How can I apply nav area in spline mesh runtime?

Hello! Contact me in Discord - klauth86#1475, we have some prototype classes…