As far as I know, isn't WN the only airline that will refund part of a RT ticket in a proportional manner if you don't use the full ticket?

Like, most airlines calculate fares as A-B-C with A-B being front heavy in price with B-C costing next to nothing. Thus, if you fly just A-B you get next to nothing back for B-C, but WN is the airline that doesn't front load fares making it unique.

And in terms of an international fare, irrelevent. Most airlines will do A-B front loaded in price.