From what I can tell, until we hear from a DEV, these are simply unintended map irregularities that can be exploited by certain tanks/situations.
Its NOT illegal to use them if you know they're there. No one should get blacklisted. My sole question is : do they give an unfair advantage to certain tanks or certain North vs South spawns.
Truthfully I"ve tried a few, with no success. I've also been rip-sawed by an E-25 (NOT Gasai!!) who was in one of these spots. My response was: good for him, he knew how to exploit the map/tank combo he was in..