My Route is Jakarta
If using any airline other than BA , buying the tickets in London is easier
If with BA better to buy in Asia
I manage it a few months in advance but if flying frequently (3 times a month) i will always buy ex UK with OW or Garuda
Ex EU is cheaper , but the extra time taken is worth the saving.
If i want fully flex BA CW , buy in Asia , even I Class is refundable