Ah, fair enough. The 1Y is a great motor for 4S.
I don't know anything about planned rules from the BRCA, but I do know that ROAR in the USA are planning on limiting voltage to 4S...and I can't see the BRCA going against that. Personally I don't see why they can't raise the bar to 6S, which will allow much more flexibility and no disadvantage to 4S users. But that's just me, lol.