whoa, 1/2 turn off hardest! this seems odd.
of course every car differs, so too your preferences, and i have no direct experience with the 147. however, i've had KONI Sport dampers on 3 cars now. first was a '94 MR2 with aftermarket springs; the dampers ended up around 1.5 full turns away from soft towards hard. in my 156 which had Eibach springs and a fully loaded boot (with stereo equipment) i had around 1 full turn in the rear, and 3/4 on the front (away from fully soft towards hard). now, in my GT, i have them around 1/3 of a full turn away from fully soft towards hard on the front, and rears remain fully soft (partly cos i haven't removed the boot trims to access the dial).
from fully soft to hard is about 2.5 full turns, right? to think you're having to go over 2 full turns seems strange. what springs do you have?
in general, you shouldn't go 'fully hard' as this virtually locks the dampers out, and they will fail sooner or later. are there any mods to the car? carrying extra weight, aftermarket wheels, etc.
maybe what you need is uprated springs if the car is soft, and not just dampers. the dampers will provide superior rebound control, and minimise bounciness over bumps. i would have thought that soft is good, in terms of ride comfort.
basically, i would use the dampers to control the bounciness. this does not necessarily equate to hardness. if you want harder suspension, then change the springs. if you want less roll around corners, change the rollbars. but as you uprate the springs and rollbars, you'll not only get increased hardness, but a loss in ride quality, and ultimately if you go too far, a REDUCTION in handling on anything but billiard table smooth roads. around melbourne, you will need some compliance to avoid 'skipping' over bumps, especially around corners.
i'm in no way a suspension expert, but i'm not clear on what your experience is and what you're expecting. also what level of expert advice you've had. but i think you'd benefit from an experienced suspension person to drive your car to help set things up, and maybe some new springs.