Adding multiple versions of casks

[domdomegg]

I'm looking to add Postico 2 as a cask. We already have Postico 1, which is still maintained by the authors and many people only have a license for Postico 1, so I think we want to keep this version.

The instructions on adding new software indicate I can add new versions with an @ symbol: https://docs.brew.sh/Adding-Software-to-Homebrew and https://docs.brew.sh/Versions

I don't think I've added a cask before, so apologies if this is wrong but I don't think this is supported for casks. I couldn't find an example of a cask that does this, and looking at the postgresql Formula for inspiration here trying to do this results in the error:

audit for postico@2: failed
 - cask token @ should be replaced by -at-
 - cask token should only contain lowercase alphanumeric characters and hyphens

This is what I have so far: Homebrew/homebrew-cask#144285

I'm leaning towards adding a new cask called postico2, given this scheme seems allowed in the Versions documentation (search for 'formula2') for things that don't share a codebase - not sure how this applies to casks where we're not sure whether the apps share a codebase or not.

What's the recommended approach to go about this?