Id rather a cableway than a light rail spur, because it avoids the narrowness of SW drive, can be more direct, and has a bit of tourist appeal.
Doing a light rail branch so close to the systen core invokes the issue of dividing frequency:
http://humantransit.org/2011/02/basics-branching-or-how-transit-is-like-a-river.html
If you have a track pair, branching means only 1 in 2 trams can serve each side of the branch (you can also do something god awful like "one tram in four" but that trashes legibility and would lead to uneven passenger loading)
If you have to do a branch, it needs to be towards the end of the line so the division in frequency doesn't have a negative impact.
Think of the way in Brisbane the split between the Ipswich and Springfield branches happens at Darra...Works well because outbound of Darra the population density drops off, so only having half the trains to each branch is bearable because demand at each station is lower.
Whereas on the GC doesn't work because you are splitting the frequency at main beach, even though Southport, GCUH etc have heavy demand and would suffer.