From memory from playing with the AFR lockup table eons ago, the PCM disables fuel trims when the air/fuel ratio commanded is different than stoich. I had the lookup tables enabled and the BLMs or...

I have used 25-30 mph for lean cruise for years. Plenty of times you are in 2nd or 3rd gear with the converter locked at no load in traffic where you are wasting fuel.

$OD can have the parameters...