I've rode the Profile one a few times.... the whole pedaling back just to disengage it is way to weird for me.
That's how every coaster works. You always need to back pedal to get the full amount of slack.
If anyone is interested:-
As far as I can make out, the Z-coaster works by having the pawls have an extra little "leg" on the inside that sticks back behind the pivot. Inside the driver there is the ring with three cams on it that can push these legs out to retract the pawls against their normal springs. This ring has an internal stop that dictates the "slack" and this runs on the outside of some sort of drag element on the axle that I cant see much of.
I am not going to make any judgement on how well or otherwise this will work because I will get too much shit for it but I hope this is informative. Sorry if I got it wrong and there is something else going on.
G.