Yes, I think it goes below 0 on lowered 4x4's, and could flip to a really high value at the limit of travel.
I can attest to the fact that once the TCA's on the front go inverted and point upwards the handling becomes horrible. My car at one point was inverted at normal ride height. Mark is looking to give me as much room as possible to correct the car. For instance the WRC front cradle has 2 mount points to raise the TCA and if we have room the whole tunnel and strut tops will be moved up by an inch or more.
The rear WRC cradle will be moved up about 1 inch in to the boot floor from the normal WRC escort starting point. All 4 shox will be equal length as they are all front ones in reality (i.e. front being used on the rear too)