Imagine that you have several objects scattered in the scene and you want to replace their submeshes… is there any chance to make that?
As far as I tried when I replace the subMeshes everything seems to be void.
Thank you!
What would be your use case for that? 
Submeshes depend on the geometry data of a mesh, so copying to a mesh with a different geometry is not something expected.
And how could I replace the geometry data but keeping materials, position, references and so?
Thank you.
Thank you unfortunately it seems than having a really different amount of vertices introduce problems, my idea was to use a simple mesh as dummy and replace it with a high resolution one later.
Oh that’s already well-supported in Babylon, no need to roll your own solution:
Levels of Detail (LOD) | Babylon.js Documentation (babylonjs.com)
Progressively Load .glTF Files | Babylon.js Documentation (babylonjs.com)