i tried it piecemeal the first time, but after a couple of rides, i said, "screw it", and chopped it all off.
OTOH, i'm now in the process of assembling a new bike and will have to cut the new steerer tube on the fork. i'll probably leave a couple of centimeters on there, as long as i can find some spacers around here. but if i can't, i'll just ride it around the block a few times without them and see how it goes.
i bought this 50cm frame with the intent on getting my handlebars lower, so it wouldn't make much sense to dick around with spacer too much and be a p***y about it. so i'll, go big or go home, i guess.