Do you crab or forward slip in X wind landings

Side slip for all the above reasons, especially for instruction. Translating from crab to slip in the flair or just at touchdown is unnecessarily complex. Establish the forward slip on final and hold that attitude until stopped.

However, I commonly "cheat" whilst flying the tug, crabbing until short final and then establishing the slip. Less pressure on the rudder foot/knee if doing lots of landing in the Pawnee.