Searchable flag for hardware token in entries

A Flag that can be set in an entry if the entry got secured with a hardware token as 2FA. Currently there is no searchable flag for this scenario. I can either use a TOTP token or a custom field that is not searchable (mobile app).
The Vault Item Labels could be used for it too if searchable.

Example: I want to search for all entries which use a YubiKey for authentication.

A possible work-around right now is to put some sort of emojiis in the name field for the different booleans, and then you can search for the emojiis.