You’re most welcome and, thank you, for the additional context. The fact that “public” is green confirms your S7 is provisioned for coverage with Republic’s GSM cellular network partner. It’s probable but not guaranteed moving the SIM to any 3.0 phone listed here will work.
Republic does suggest use of a fresh SIM when activating a new phone for the best user experience, however, doing so isn’t mandatory. If the plan is to bring a compatible phone purchased from a third party I would suggest acquisition of a new Republic SIM as best practice. You may purchase from Republic or from Amazon. This way, you’ll have a new SIM if needed. If you choose to purchase a new phone from Republic, a SIM will be included.
For what it’s worth, I’ve moved a Republic GSM SIM from one 3.0 phone to another 3.0 phone on multiple occasions. My experience is usually but not always doing so works. @bocephous, this is why Republic suggests a new SIM and doesn’t document moving an already activated Republic GSM SIM between phones.