I called in about this, especially the transit issue as there seems to be a rule right now that for transit, it must be one itinerary. So I thought about paying for a Scoot ticket for HKG-SIN then connecting with a First redemption SIN - LHR but the agent seemed clueless and just said I should call back once booked and they’ll try to solve it. Didn’t sound convincing and I think it’ll be trouble. Too risky so better to find awards on SQ only.