It's like the transmission in your car. Low gear gives you lots of power but not much speed. High gear doesn't give you as much power, but goes to a much higher speed.

A less restrictive cap tube gets there faster, but the temperature isn't as low. A more restrictive cap tube gets there slower, but goes to a lower temperature.

All of the existing cap tube charts assume you want to get there faster. None of them are designed for lowest temperature, which is what we want.