Steve, are you referring to the changes in formware 1.8.3 (vs the previous version 1.8.2)? The changes are all documented in the GitHub commit messages, and README.txt. For example, the commit message of 1.8.3 says:
main changes are 1) added back support for concurrent running mode; 2) new ‘device_id’ option which allows modifying the last byte of the controller’s mac address.