Can I rely on workshop items navmesh instead of making navemesh for an edited cell?

[ATuMod]

Few years ago I mad a mod that added an underground level to red rocket. I removed it becasue of collision bugs. I fixed those bugs but I can't seem to fix the navmeshing proplem.

 

I can't get npc's to walk to these stairs . But If I teleport them at that red step and command them to they go down the stairs.

 

I've pulled my hair trying to fix it then I got an Idea. What if I completely remove the stairs and that red step and leave it empty and rely on the player to build their own nave-meshed stairs. Would that work?

[deadbeeftffn]

the link doesn't seem to work...