As far as I understand the navmesh modifier volumes, they wouldn’t solve my issue.
As I said in my post, if the AI has to go through Climb1 (i.e. it’s a pre-determined path by a level designer), it should use it regardless any building, because it would destroy them as soon as it gets close enough to hit them. If I would use the modifier volumes, the AI would immediately follow Climb2 in case of presence of buildings on Climb1. And, as far I understand how path finding in UE works, if both climbs are filled with buildings, the AI would fail to generate its path up to the crystal (which is supposedly placed on high ground), so, I think, that’s not what I’m looking for.
I appreciate the reply though. 