You can pick up improved meyer trees almost anywhere, so I wouldn't worry too much. Obviously, you're experiencing tree ripe Meyers vs store. But given time, a new Meyer would give you the same results. But we do love our tree children!

FruitMentor youtube channels (which are in partnership with Univ of California citrus programs) are very good guides on citrus propogation.

You don't indicate where you are, but since it would appear in ground with a Meyer, you are likely subject to greening quarantine (most citrus areas are covered). So, please check both your existing location and destination on their quarantine status (and also, any places your plant would have to travel through en-route).

Rootstock for temporary use could be grown from any citrus seeds. An educated decision on rootstock appropriate for soil type, disease, and climate conditions should be made for any final planting. A local citrus nursery at your destination. would likely have chosen a rootstock that would be desirable for the location.

https://www.fourwindsgrowers.com/collections/citrus-rootstock