I'm in the same position. At some point they combined by Aer Club with my standalone Avios account. It hasn't mattered so far but presumably we'll have to tell them to combine it with BA and not leave it to EI (unless we will be able to combine to/from Aer Club).

Sounds like there will also be a strange period when we're giving our Executive Club numbers when booking on Flybe.

Glad it's all being simplifed