Question Splited mesh and navmesh

Am I allowed to have one mesh for navmesh which has many smaller planes?
This is one object but has many planes next to each other.
Does Unity allows so many vertices on top of each other for navmesh and further for Lightmapper?

I have to plan ahead.

 

Yes, it does work, already with your small example you could try it out

Small Edit: You can create a NavMeshAgent, size it as big as needed.

Take Care: You have those planes aside of your "Main Object", if they have "Colliders" which can collide with other objects, it can happen that you will get stuck since the NavMeshAgent will not calculate that within.

If you want that to be calculated, then you will have to make your NavMeshAgent bigger which leads to the demand of your baked area to have bigger paths to move on