FC constraints question

I have a couple questions about using the constraint field in an FC set.

1. Is there a way to constrain to a list of possible values rather than a single value? For example, something like modResource.parent = (35,56,78).

2. Is there a way to generate the constraint from a snippet? For example, a constraint like above, except I'm returning a list of all the resources with the alias "foo"?

3. Assuming the answers to both questions are "NO", is this a feature request that is within the realm of reason? Or am I being ridiculous again?

#1 and #2 are irrelevant, as:

#3: Yes, No.