Originally Posted by
svs-dhm
Usually they only have two seats available in biz,
...
In other instances, I've booked the two available for biz, then bought economy for the other two and used miles to upgrade. Its the next best option.
Are you saying that the availability for miles upgrades is different to the availability for straight redemptions? The T&Cs suggest that they come out of the same bucket (fare class I/O).