The solution I came up with is based on 3 main hardware components, and 5 software components.
Users of the Pay Pal or Braintree Android SDKs must update to the latest version.
It may be possible to predict / error correct for the fluctuations however I opted to go for a simpler approach of just plotting tags next to the reader with the highest signal strength (the one they are nearest to).
This now means that readers need to be placed in each room (ideally centrally) where tags need to be tracked and it is only possible to determine a tag is in a room, and not its position in that room (although it is not used the original trilateration code has been left in the download).
For more official, relevant information, see the 2017-2018 Merchant Security Roadmap Microsite: See also Updating Your Production Environment to Support TLSv1.2 on the Braintree blog.
Merchants must verify that their systems can use the TLSv1.2 protocol with a SHA-256 certificate.
Pay Pal and Braintree are updating its services to require TLS 1.2 for all HTTPS connections.