Some cool ideas here provided cost is not a factor.
You would reconfigure Westpac using the budget that the council is setting aside for a new indoor concert venue. The old souther stand would be the seated part of a concert venue.
It wouldn't be multi purpose though, basketball, etc. Would have to stay in TSB arena, but this venue could be used for concerts, lectures, exhibitions, etc.
My understanding is you simply can't recomfigure Westpac. It would be nice, but it can't be done in anything like a cost effective way. Because of the way it was built if you change part of of it the whole thing needs an overhaul...the circular shape, with symmetiral loading is what holds it together. Any reconfiguration (other than setting up of limited extra seating inside the playing circle but outside the rectangle, would require massive rework. The superstructure would not support additional stresses created by extra seating etc.
So you'd have to knock it down and start all over again. It would be cheaper.
That's unlikely to get approval in the extreme.
It is on that basis that I was looking at alternative sites for a purpose built stadium on the model of the Seattle ground.
Yeah the idea though would be to build two completely separate stands in front of the old stands with a new roof structure, etc, and use the existing side stands. So you keep the circular stadium but rotate the pitch 90 degrees and put new structures in front of the north and southern end of the stadium.
The old southern stand would then be semi circular seating for a new indoor venue (if space allows).
The venue would of course not be multi functional from then on, so cricket would need to go to the basin, and the ARL would probably stop coming.