I remember flying MNL-BKK (DMK) on LH more than once back in the '80s as well as BKK-KUL and SIN-JKT more recently. These fifth-freedom tags were often cheaper than the local Asian airlines before LCCs arrived on the scene, as there was always the risk that he incoming flight from Germany would be delayed.
They also had the advantage of departing in the evening (on their way to Europe) well after PR or TG, giving me a full day in Manila without having to take an early flight to Bangkok the next day.