EDIT2: I just successfully converted all the exterior lands with statics/buildings/NPCs/creatures for the TR_Mainland.esm. See pics in post below.
EDIT: It turns out my methodology converts the statics/NPCs just fine, so I may be close to being done with the project. Check out my screenshot of firewatch castle a post below.
I just finished converting the heightmaps and landscape textures from the latest Tamriel Rebuilt release (16.03) to Morroblivion. I think I've come up with a solution to my previous problems with some regions not showing up. This is just a test conversion to figure out out the best method of a more complete conversion. There is no region data and no statics. I initially thought about converting statics separately and merging it with the landscapes, but I believe converting both at once will make it easier to keep all the IDs synced properly. My goal with this project is to convert all the TR lands, statics/buildings, interiors, NPCs, and creatures and to Morroblivion. I have no plans to try to do the dialog/quests or AI yet.
I haven't asked for permission to distribute a TR conversion yet, so no ESP for now. I'll try to post screenshots in a few minutes... edit: set them up as jpg attachments rather than images for easier reading.
BTW, the first and last screenshot are using my conversion of Vurt's Bitter Coast Tree Replacer II (LODs and collision meshes are still WIP).