If he makes the collision mesh the exact same as the terrain mesh, it will have many problems, like raycasting.
I had a few ideas how to solve that, but never got around to work on the thing. I basically just started, school got in the way, and then I forgot.
Also, that terrain was created by parsing the .ter file, it can convert any map.
That looks infinitely better than gross textures from the 90's and mediocre smooth shading.
The idea was that if you don't like smooth shading or textures, you could simply turn them off in the converter.
The only real problem I ran into was the size of the geometry. A tork terrain loop is 256x256 grid squares, each of them has 2 tris (diagonal split). This results in 131072 faces. These all have to be saved in the blb file. The blb generated for this test was 35MB. You can imagine how long that takes to download through blockland? And that's without collision shapes. Those might double the size. It really isn't feasible unless it's for some kind of single player gamemode, or you have all players download the add-on externally before joining your server.
Edit: At least I used blbs because the performance rendering them is much better... I can fit the same 131072 tris in a 3.5MB dts but I'm not sure about the performance.