So just for giggles I revisited this on my Jeep.
Tune is accurate/good...BLM's & INT's hover around 128 +/- depending on temps etc.
When lean cruise is active
BLM's drop to ~118
INT's still hover ~128
o2 sensor voltage drops to 100mV or below
rich/lean states lean.
Is this normal behavior, I don't recall because it has been many years since I played with it or for that matter actually data logged this thing.
