Hello!
I’m confident this is an easy answer, but I can’t seem to find it. 
I am putting together a form where people can sign up for an event on a first-come-first-serve basis. How would I go about disabling a list item once the responses hit a certain number?
Once a response hits 10, I want to disable the selection of that option.
Answered my own question!
I added a column in my lookup table to count the number of times the list item was chosen in the form table. Then in the lookup settings of the form table, I set a filter to only include those in the list who’s count is less than 11.
Side note: Wishing we had a “less/more than or equal to” option so we can use real numbers.