B.A.T. can can handle Models/Textures diffent, Stock Game/Modacts other Modded Installs can't handle.
We had a Discussion with Mike lately where he explained it. I didn't caught the Tech stuff.
Since the release of 4.0 Users from 4.0 BAT are hanging in the Lines.
Though some intermix content. When they must stick to 4.0 prepped Mods or get to know
Mods clearly stating BAT latest only, is not their business.
You should request a BAT 4.0 Section for having a place to settle down, move along with all the 4.0 Users.

If you need Help and Support just say it, having different Game Installs in 1946 is not new.
Having your own Section would be wise and the logic next step.
It can avoid trouble in the due course.
What I know for sure, 4.0 content and BAT latest Mods clash without a doubt.
It shouldn't be underestimated that official BAT support ends at everything not latest Version.
Best wishes
Tobias