Honestly I have no idea how overrides behave regarding navmeshs. You can still fix it and see how it goes. But tbh, I just downloaded the mod to have a look, fixing it properly just with an addon seems crazy... there is a whole bunch of wild dirty edits.
And about my previous post : I'm not used to work with worldspaces (aka "exterior" cells), but I guess the trick wouldn't work for terrain edits, so exteriors wouldn't be mergeable anyway.
Thanks, I guess it's a try and see situation. I'll PM Zilav first though and ask him about the navmeshes before wasting even more hours on it than I already have.
I understand what you are saying. This mod has a lot of issues which I wanted to fix. I just started with the navmeshes, but the authors don't seem to be interested for whatever reason. I guess they plan on returning to it someday.
As for the exterior cells, the author told me it was designed like that because he'd originally planned for the "trophy hall" to be in the same space but changed it later. He openly admitted they were learning the CK when building this mod. I'd just build my own if I could use that sorting system they're using, but they're not going to part with anything from this mod anytime soon so I'm just have to hope I can fix some things using an addon