When you do your bench test, you are leaving out an important varible. You need to have it attached to something that it 200' and will hold 200' for a number of hours. If you conduct the bench test using actual operating conditions, you will find a it to be a different answer.

Mine dries up some, but not enough that it will not start instantly.

It's impossible for it to drain back, meaning that if it drains back, you have a serious carb problem that will show up while operating the car, specifically severe load-up.