Further, some OW destinations are not listed in the online tool (which is limited to about 250 airports). The search engine gives different results depending on how you search. Eg search for LHR to SYD on a multicity and the results will not necessarily find all the options that you can see when manually doing multiple searches LHR to xxx and xxx to SYD where xxx is SIN, BKK, HKG, MEL, AKL, PER, BNE, LAX, etc.