Originally Posted by
Raffles
No.
AFAIK, only IB flights are cheaper when you book via Iberia Plus and not BAEC. Although I have not checked everyone.
Second, partner airline bookings via Iberia Plus - and this includes BA - have nasty cancellation penalties. It may even be 100 per cent forfeited, I can't remember. But it is not pleasant to anyone used to BA' 'get it all back less £30' policy.
UUUUF! I overcame laziness and went to check for myself. You're right, the IB+ penalties for cancellation are very nasty; and the prices are the same as, or worse than, BAEC for non-IB (e.g. CDG HKG on CX).
On a different tack, BAEC offers KUL HKG in C for the same Avios amount on MH and CX. but the charges seem to be about double using MH flights.