Is there currently any way to search for cards with only a single printing in Magic's history?

I came across an EDHREC article (https://edhrec.com/articles/single-combat-hapax-magic-a-true-singleton-format) proposing a new restriction they call Hapax, where the only cards allowed are cards that only have a single printing across MtG's history. I'm curious about what that card pool looks like but from what I see in various search filters, there's no way to search for cards with a single printing.

Am I not seeing a certain filter? Or is this a feature/filter that could be added without too much trouble?

Alternative, this can be done at Scryfall https://scryfall.com/search?q=set%3Ac16+papersets%3D1
So with this, you'll get all unique cards within the set Commander 2016. If you do it open-ended, there are 16,797 total unique cards.

freakwerks wrote:
Alternative, this can be done at Scryfall https://scryfall.com/search?q=set%3Ac16+papersets%3D1
So with this, you'll get all unique cards within the set Commander 2016. If you do it open-ended, there are 16,797 total unique cards.

Yup, I already found the search string at Scryfall, but I want to be able to see the list against my inventory here on Deckbox if possible, so I know what I have available to me now for deck building with that restriction.