I think this is the right spot to make folks aware of this. In Mids', at present, the tanker ATO set cannot be used in Blazing Aura. That is consistent with when the ATO was released. However, I'm not sure when it happened, but a couple of days ago, I respec'd my fire/fire tank and was able to slot the Superior ATO set (a friend was able to slot the unimproved ATO set in theirs) in Blazing Aura.
Sorry to give you good people more work to do, and my apologies if this is in the wrong place.