If you dropped 2 jet sizes and found no A/F improvement, then you may want to to go back to previous jetting and look elsewhere. Dont worry about WOT until you get the Idle, the transition and the cruise A/F correct.
If your metering blocks do not have screw in idle feed restrictors, then i would suggest tapping them or buying replacement blocks that have this feature. If you really want to nail down your transition A/F readings, then you will need to be able to tune this part of the circuit.