I think that 30 seconds isn't long enough. The extra 15 seconds will keep play faster and not incure stroke penalties because 32 seconds were needed to change clubs and line up the chip, pitch, flop, putt and any other shot or club change needed.
Agree!
I think that something in between would be good. The 30 second one is not long enough to line up putts or take a look from two cameras. I think something in the 50 second range would work.