I2C interface is compatible and you can read/write it if you have adapter with CFP compatible connector, so I guess you are asking about adapter for CFP/CFP2/CFP4, right? We do not have it in plans, and to be honest, we do not have much questions about these
It was mental shortcut, because as I remembered it's quite similar, e.g. MDIO is SDA, MDC is SCL, it also starts from A0 addr, but my mistake - you are right, interface may have totally different implementation, I've never used it so I do not have experience in this field.