Just because they say that does not mean it's correct or the only way to tune.
I feel like the tuning school must have trapped you in a basement somewhere where they forced you to preach their tuning technique like some sort of calibrating bible.
The calibrated success books and DVD's from what I recall never said to fully disable power enrichment while tuning.
You already know that doing it the way I have said or others is perfectly fine.... PART THROTTLE AND MEDIUM THROTTLE WILL NEVER ENTER POWER ENRICHMENT BECAUSE THE THRESHOLDS FOR DOING SUCH TUNING NEVER MEET THOSE REQUIREMENT.
But you argue it anyway because the tuning school said differently.