quorn, you mentioned this takes up the same space as the original Firemoth, yet also talked about improving the landscape. Did you add any landscape, or extend the island in any way? I ask because Tamriel Rebuilt's Map 4 comes right up within the same cell as Firemoth, and actually adds some sea-floor detail to the Firemoth cells.
The island has the same shape, I didn't change or add any more land. The only thing I did was smooth out some of the terrain that was excessively blocky, and fixed all of the texture seams by repainting some of the areas and placing objects over unadvoidable seams. I am thinking of adding a dock at the base of the hill to the guard towers, since Firemoth Fort was suppose to be a stronghold guarding the Inner Sea, and it really doesn't make much sense that there is no accessible dock. Plus it would fit with the lore I'm including that Firemoth Fort was originally built to deal with piracy and smuggling around the Bitter Coast.
I originally tried making all of the cells of Firemoth interior cells, which I do have a proof of concept http://www.gamesas.com/bgsforums/index.php?showtopic=969126. The smoothing and seam-fixing of the terrain was originally for the interior version to clean up the created interior landmass meshes as a result. Unfortunately, the performance hit recreating all the cells used by Firemoth was unsatisfactory; it was too choppy, there were stability issues when encountering a large ammount of skeletons, and the local map had a lot of display issues due to the size of the landmass. However, I'm going to revisit that concept when I finish this, I think just using the two main islands of Firemoth would fix the majority of the issues encountered rather than recreating the whole island. Afterall, having it completely interior would solve any landmass conflicts, and have this expedition accessible to everyone as a result. ^_^