Short shifters can be a mixed bag. I've installed a few different ones on various cars and generally I hate the way they feel. Sure, they shorten the throw, but they do increase shift effort. Especially if you're going to be doing a lot of rowing, like at a track, any extra effort is unwelcome.
But it shouldn't take THREE TIMES as much effort! Something is wrong and you should probably not drive the car until you find out what it is. I'm not familiar with anything on a Porsche tranny, but it sounds like you definitely have something installed incorrectly.
The bit about the shift knob (I'm looking at the
instructions online right now) is that they're telling you to remove it, and they're saying that some cars have a set screw that takes a 5mm hex key. Vague of them, but not inaccurate--they should've said that it usually just pops off.
The installation looks pretty complex on the Boxster, but the one area where I could see problems cropping up is in the cable end adjustment. If you're feeling like the shifter is taking too much effort, I would guess that the end links are too loose or too tight. You should be able to shift easily with very little extra effort when the car is off.
Other than that, the "free play" adjustment they talk about with the set screw on the aluminum bushings could be an issue maybe...
Sorry, can't help you more than that without actually being there and playing with things.
