Thanks Bill for your prompt reply.
I have been using Ripmax UK as they have all of the legacy firmware on their website as well as the latest versions, this is something Futaba USA & Japan do not do. I have compared the code for the latest versions from both sources and cannot see any difference, so if my theory is correct it would seem the code is the same. The revision document also suggests they are the same. What concerns me is that Futaba users around the World have been forced to adopt the inferior EU protocol.