Ideally, if possible maybe try and keep the same rake-angle as standard.
i.e. the height difference front to rear.
Measure from the centre of the wheel vertically up to where the measuring tape touches the curve wheel arch.
If you raise the front relative to the rear, you will add some understeer, obviously raising the front at all over standard will increase understeer too.
..you also get more understeer if you lower the rear relative to the front.
Having the rear slightly higher than the front compared to the standard rake angle is okay (say 10mm), it reduces understeer but if you overdo it it would have a negative efect effect on stability.
I can tell you that it makes an enormous difference lowering the front, but the main issue is ensuring you have sufficient front ground clearance on bump=y roads and parking ramps etc.
The KW2s are just rebound adjustable I think, so you will have to be relatively sensible in chosing how low to go.
-15mm at the front should still be okay I would think, but start off conservative and just enjoy driving without bottoming out for a while before going too low
