I used a floor jack to compress my front KDSS piston when I did my lift install, and it still performed ok off road.
If you have 2 car ramps, decent height ones, stick one under the front drivers wheel, and one at the rear passenger wheel and drive up onto them. the front piston should compress, and the rear should extend.
Yes, did this with a dirt slope around 2 feet in height near my house. It was on the passenger side. Rear piston compressed perfectly. However the front piston didn't move. I'm going to do some solenoid checks as described in the service manual and if I don't find anything there I'll take it into the dealer.
Not sure where I will stand under warranty now that it's been lifted.