I want to use a GUF2 to fly to an Asian destination which is not served by BA.

This will entail flying into one of HKG, SIN or BKK on a BA ticket and then connecting to another flight which will have to be booked on a separate ticket, and then v.v. on the return.

If using HKG as the gateway I could probably use CX for the onward connecting flight, although I assume that I will not be able to check my bags through from London.

My question is which of these gateways is the best in terms of logistics, assuming I have to clear immigration / customs and re-check my bags ?

I know HKG well and it would be my natural choice. I have not been through BKK for 10 or more years (when everything was very slow and chaotic) and have never been through SIN (shame on me !).

Any advice welcomed on which is likely to be the preferable option.

Any anecdotal experiences of trying to get through checking of bags from LHR onto CX if on a separate ticket also welcomed.