You can get around this a bit by assigning minimums in the material definitions tab. Ie you can define one stud rail set with a 3/4" stud and 15 anchors minimum. Another with 3/4" stud, 20 anchors minimum and then if you see in results that you need 18, you can just re-assign it to the 20 stud configuration and it will run the check

Thank you for submitting this suggestion. This enhancement is in our product backlog and one that we would like to add in the future.