But you can move out of a MQ at any time. You are not obliged to stay in MQs for the duration of a posting.
Eg: Arrive at new Station for a 3 year tour and move into your MQ. After 9 months, find a property that you want to buy and move in at the end of year one. Housing then demands you continue paying MQ rent for the following two years because that's when you are due posting. Don't think so.