Automatic Idle Adjustment One Person HOW?

How much time do you spend at stop lights and such? And how much of that time does the engine spend in park and neutral?

You want to tune the carb WITH LOAD ON IT not when there is less load on the engine.

It makes ZERO sense for the guys running leaky slush boxes.

It makes no difference. If you tune your car to idle at 650rpm in gear and then you put it in neutral and you're at 750rpm and I tune my car at 750rpm in neutral and put it in gear and it reads 650rpm, we just arrived at the exact same spot except my car had zero chance of rolling over me or into a wall.