Actually there is only 1 flight that day (Tuesday night) Therefore no alternative.
Should I ask for a ticket extension or just goto CX/VS to avoid the waiting game?

I am just surprised QF is holding back the inventory given it is a Mid-week departure and both CX and VS are showing "9" in ALL booking revenue class.

I am not sure it is some bug or delay at QF's Yield mgmt that is not releasing the I Class group (given it is still "9" in ALL other class)