Changing upgraded flights

[frequentclicker]

I have tried getting the SQ call centre to answer this but haven't got anywhere so I was wondering if anybody knows how the changing of upgraded flights works with SQ.

Say for instance, if I book a premium economy ticket from Singapore to Sydney and upgrade that to biz, can I then change the flight to the Singapore to Canberra flight in biz or does SQ not allow that?

 

[frequentclicker]

I finally managed to find an answer. Flights booked in PE and upgraded with points can only be changed to other flights that have a PE cabin and also have award availability for the same dates. If the flight one wants to switch to does not have a PE cabin then the entire ticket has to be cancelled and a new booking made from scratch.