Well, I tried..and apparantly I failed.
First I used the Move Worldspaces function on the file when it was still only .esp. Then I generated the LOD in the Heightmap Editor window, saved, tested ingame: failed.
Secondly I used a backed up version of the .esp, converted it to .esm, then used Move Worldspaces, generated LOD in Heightmap, saved, merged ,esp with .esm to reflect changes, tested ingame: failed again.
As I'm writing this I realise I may have forgotten to delete the LOD files, but this one is a new mod from the previous ones, so I figured it wouldn't make a difference anyway...or am I wrong there?