This idea is sprouting from my original question post, Limit number of times something can be selected.
It would be a great addition to the web designer and connect to be able to limit the number of times a choice in a single (or multi) selection can be chosen.
For example, if I have choices A, B, and C, I want to limit the number of times that 50 can be selected and submitted. After this, you would only be left with choices A and C.
Some sample uses for this could be signing up for time blocks, sessions, or a requested visitor so that a cap can be placed on how many go to each.