While we're on this upgrade issue, let me assure you that one thing is for sure.

Travel agents, other airline staff and SQ's own employees (exception - manangement staff on company business) CANNOT buy a discounted ticket in Business or First Class.

Other airlines permit travel agents and other airline staff to buy discounted ID/AD tickets at 75% and 50% off and they get to sit in confirmed Business or First Class cabins.

But on SQ, even if you're the company director or manager, SQ will not allow you to purchase a discounted premium ticket. You can only buy economy and NOT get upgraded at all !