Let's see what the FAA has to say to abondoning the 6/6 in favour of annual proficiency checks which is part of the EASA requirement for the bi lateral.
The US and Canada were able to achieve an agreement as the have similar training regimes and similar currency requirements.
I personally think you are hanging your hat on the wrong peg pace, but please feel free to throw it back at me later if I am proved wrong.
I just don't think there is enough common ground to allow a simple 1-1 exchange.