The grid (NStcData) does have this information. If the second bit is set, it means you can't shoot through (so for example values like 2, 3, 6, 7, 10, etc.). You can do
to check if that cell can be shot through.
There is no concept of height for anything gameplay wise or server-sided. It's purely visual and client-side only. If you can't shoot "up" or "down", it means there's a wall between that can't be shot through.