Customer Service contradicts themselves on a daily basis. You really have to take what they say with a grain of salt. It's your game thought, use whatever ruling is more fun for you and your group.You can rule it however you like, but the tech support people gave a specific example for Stinking Cloud, which has identical rules with a smaller area, and said that the start-of-turn damage does not get bonuses, because it's not the direct result of an attack.