I think it was just a set-up choice, Albert Park has a few straights but it’s not known for being a top-speed circuit, maybe Red Bull switched theirs off and found better time with a more stable brake balance? I’m not sure about the mini-KERS yet though, for one it would have to charge energy, though maybe minuscule amounts to make it barely legal, it sounds like something Red Bull would do, but apparently they’ve used KERS in practice so I’m not convinced it exists,