LGW-SGN via ASB on T5, $326 OW and $653 RT

Not a particularly good deal re: points earning (no frequent flyer program or partner earnings AFAIK), but could be a fun opportunity to try a niche airline and a niche airport I guess? Runs every Wednesday to/from London and Ho Chi Minh, with one ways being the same price as a round trip. Haven't been able to find it on Google flights, but appears to be bookable on their website and a few other OTAs - also haven't been able to see the fare conditions so I've got no idea if a stopover's…