xLODGen was dropped at the last minute cause of an issue and then made not a priority due to the addition of Landscapes - Cathedral Concept. It will be revisited at some point so the installing of it was left it.
Not sure about Frostmere Crypt. I've ran through it and didn't have any issues. I ran around the exterior and didn't see any issues either.
Thank you for looking into the terrain issue. I ended up creating a new profile and installing just the guide mods in accordance with the guide. I'm still having the problem. I'm missing exterior terrain beginning at the area beneath Frostmere Crypt through the Hall of the Vigilant. I checked xEdit and I'm not seeing any mods affecting those areas that I think would result in such a problem (Dyndolod and USLEEP). I also checked the game I was playing pre-guide (same masters) and it does not have this problem. I'm not trying to make this a big issue - it's just something I noticed and can obviously avoid. If I find out what is causing it, I'll update this.