One way redemptions are half of the round trip points, so simply book my trip as two one ways and I can avoid the fuel surcharge from HKG - LON. Moreover, if I decide to fly back HKG twice per year (once in December and once in January), I can book it as HKG-LON Jan outward and December return as my December race dates are known early in the year, or book December outward - January return.

This article says Hong Kong to London is one of the best value redemption because of absence of YQ. Moreover, as I also have a balance of BA Avios and BA also does one-way redemption with half the round-trip cost, I can mix and match airlines when needed as well (although they both work in similar schedule - morning vs afternoon flight can be a game changer here).