This trick should work, so long as the Red Mountain mod loads LATER than Julan. Which should be the case, for most people, unless this mod has had the timestamp edited to make it load early.
You do not ever want to add/remove a mod that is earlier in the loadlist than any companion mod, because the companion mod will get reference errors, and you're asking for doubling. Which is bad and wrong and kills kittens. And companions. And kitten companions. (They exist! Emma made some!)
A safer bet would be to not load the Red Mountain mod until after you've been on Red Mountain with Julan (for the second time, when you actually climb the mountain), and then make sure it loads after his mod.
OR, somebody could make a patch. I won't rule out doing it, but I have a lot on with Julan 2.0 just now. Which I may edit to load earlier than this mod, for safety, if people are likely to be removing/ readding it to the list! /wink.png' class='bbc_emoticon' alt=':wink:' />