Sharing schema definition between two collections for schema validation (either tv4 or ajv)

If a developer wants to use same schema definition (same variable) in different collections what are advisable options?
Today we just copy and paste the same schema definition variable in each collection (Pre-request Script tab) the downside of it is when schema needs to be changes it needs to be changed in multiple places. Is there a way to share it between collection calls maybe as a environment variable? (working example would be great)

Could you not push this up to the Global variable scope so that every Collection in the Workspace would have access to it, when referenced?

It would also be a single place to make changes.

Something similar here I guess: