I agree with all you said. I think what would help the most on this forum is when someone sends off to service and gets the engine back to post it. Tell why it was sent in and what repair was made. That way a person could look through and see problems solved.
My first repair of not idling was a blown head gasket. I reported before sending it off it had foaming milk in the reg to carb tube. When I got it back I posted this. So far on the one that's at YS service now, (that would not idle) a leak around the push rod tube was found. I quit with the one I'm working on now. Since it's NOT a tune problem, I'll post in detail what it was doing and the YS service fix when it comes back from service.
Greg Newman