That only works with a suitable external flash AFAIK.
I see, would be nice if support for built-in flash was included since possibly the same ettl protocol is used in both.
Fast Ev switching was fixed a couple of days ago - are you using the latest build?
I wasnt able to change EV with the shortcuts mentioned namely half-press and UP/DOWN.
However this is working with HALF PRESS + the ring surrounding the up/down/left/right/set bunch of keys. WoW!!. This has suddenly become my most favourite CHDK feature. It even does more than the stock +/-2 EV change. This is working in video too !! (though the value displayed for EV doesnt make sense and the liveview gets partly blocked due to some bug)Awesome !! . I now just need to figure out a way to interactively control focus in video and image mode.
It would be beneficial if this(the ring for control) is mentioned in the wiki manuals. Since I just found this by accident and this is not mentioned in the manuals
This model has equivalent but rangewise restricted functionality in stock with the touch interface providing an EV slider.