Jwill, Brian talks about making the mixture fatter, or needing less fuel to hit the ecms commanded afr. This is important because that means more fuel headroom and also better fuel economy if you care about that. (I do not😊)
The car now going negative in the long term trims actually shows that is indeed what is happening. When I ran the car previously on shell vpower 93 without the ACES, ltft was always positive, since adding the ACES it continues to move the other way.