I had an idea for a feature. Today you have edge dictionaries, which are awesome, but what about an edge bloom filter. The idea is that you could use this for cases where you have too many objects for an edge dictionary.
Example use case: You are SuperMegaOnlineStore.com and you have 5 million products and your URLs for products are SuperMegaOnlineStore.com/products/a-product-identifier . You could create an edge bloom filter that contains all 5 million product identifiers, if the filter does not contain the identifier in the URL you could respond with a redirect to a not found page and avoid a DB lookup by the origin server.
If VCLs could reference POST form data or JSON bodies we could even use this in more use cases, for example if we had a POST login form and one field was the user's email address we could keep an edge bloom filter of all customer email addresses and check the email address against it. This could help mitigate bot attacks against login endpoints.
Is this something you could do?