In the iOS SDK, you can check an entitlement for a customer and determine if that entitlement is in the sandbox environment or not.  For the same customer, when looking at the Firebase collection setup via the integration, the entitlements object has nothing indicating if the entitlement was granted in the sandbox or the production environment:
 

"entitlements": {
    "pro": {
      "grace_period_expires_date": null,
      "product_identifier": "pro_1199_1m",
      "expires_date": "2024-08-01T20:03:48Z",
      "purchase_date": "2024-08-01T20:02:16Z"
    }
  },

The only way I can think to determine if this is in the sandbox is to match the product_identifier for the entitlement over to the subscriptions object and see if is_sandbox is set.

Is there a better way to do this?  For a given product_identifier, will there only be a single matching entry under the subscriptions object, or will there potentially be multiple entries?