There is no bridge here, because RWT needs a lot more information about the area, such as corner coordinates, height range, etc.
MTT doesn't need this because it just works with meshes.

Theoretically, you could use MTT to convert your mesh, and then pass that result to RWT, for example using export/import RAW heightmap.
But most likely you will have some error in converting coordinates to world position (and vice versa), and height in point.
This will happen because your areas corner coordinates and height range in RWT and Blender will most likely not match.
How big this error will be depends on how much your areas will not match.
If this is not a problem for your project, you can try.

The best way to use custom elevation sources is with RWT API:
https://forum.infinity-code.com/viewtopic.php?id=1538
But this way requires some experience in programming.

As you may know (I already made several posts about this question) I would like to have a better resolution for my RWT which don’t seem very realistic with a 30 or 90m resolution.

With Qgis, some plugins and Blender, I can create an obj with a 5M resolution using IGN 5m rasters.

As my project uses many of the RWT actions, my concern is now to replace the RWT by this new mesh, and I am wondering if I could do this with your Mesh to Terrain asset ?

I don’t see anything about a possible bridge between these assets in their documentation?

If this is not possible, I can make a workaround placing the RWT terrains without the textures under my new 5m resolution terrain.

Or anything else that would be better?

Best regards.

Philippe