It would make the HA app far more useful if when setting up a user a unique managed rfid token were generated.
The app could then offer it via NFC to a reader for user identification. Like unlocking the front door.
Obviously before this can reach full capability of letting me send an untrusted person a request to add the app and sign in to get short term access, the underlying permissions also need to be fixed or they could just access the rest of the house.