In my experience using HEAT with any AI vehicle it loses a lot of its AoE. I find that to terrible on the KT.
They used to be bugged (they where explosives weapons, instead of ballistic thus they did not collide if remember correctly) but I am not sure how they fix it. If it is straight more damage and penetration as it look from the editor the AOE damage for the same distance from the explosion should be bigger.
Testing in game did not indicate less AOE for KT.
Note that the ability does not increase AOE radius just the damage at the distance from point of impact.