Not sure if this is an enhancement or a bug. I'm getting into v12 of Forms now and am happy about all the new logic for date fields. But something odd is that, when restricting to specific days--like only Tuesdays and Thursdays--the date picker doesn't allow for selecting dates outside of the current month. So, for example in the first screenshot below, October 2, 7, and 9 cannot be selected, but once I switch to October, I am able to pick those days. (Custom CSS used to make selectable days easier to see.)
This really seems like a recipe for confusion/frustration, so I'd like to request that if I have a limit to Tue and Thurs then those days can be selected anywhere they are visible/valid on the calendar picker.