Yeah! this is mostly already supported:

  ? A date after today
  [date min="2026-10-13"]

  ? A number between 10 and 100 that's a multiple of 5
  [number min=10 max=100 step=5]

I didn't want to pack everything on the homepage example, but there's more examples in the form builder.

Also see:

https://askdown.dev/spec#4-question-types