proform secondary guidance
The first thing to fix is that 3.5 power valve. That's where you start.
I realize it's on the primary side but it's opening WAY TOO LATE.
Check your vacuum at CRUISE and set the power valve opening under that. Then tune from there.
Also, don't live and die by that O2 sensor. You can get a lean spot and not hurt anything. I trust plug readings over the O2 for most things, until you are down to the gnats *** for tuning.
Fix that power valve opening.