Ey Solarius, did you really needed to put all the files of the terrainpack into FMP?
How about you make an extraruleset file call it FMP_Terrain_Pack_Nightly.rul, adjust the terrainpack ruleset file you need and you won't need to integrate all the other files of it. Just mention that people can use it, or should use it.
EDIT: OMG he did this with a couple of other mods too, which i would have used as optional (extraufo's etc..)
I don't wanna know how you keep things clean and updated.