12:1 - 11:1 - 12:1 in the space of 300 RPM? What does that fuel map look like?

The base ECU timing was never set. At AEM 15 degrees the actual timing on the engine is 5. That isn't knowing 3S tuning, that is not knowing AEM EMS tuning. This is one of the first things you do.
Sadly, there is no shortage of soi disant "t00n3rz" out there that really have no idea what they are doing.

That's one of the big reasons why I'm so keen on owners learning to tune themselves - they have a vested interest in getting it right.

DG