Yes, Flipstick Original/01, Flipstick Extra-Long/02A & Fold-Away can easily be reduced in height by a maximum 12½cm / 5”.
Once you have determined your required height, from the top of the seat mark this measurement on the stem. Remove the rubber ferrule & plastic stem insert and using a hacksaw or pipe-cutter carefully cut the aluminium stem to your mark. Remove any sharp edges and replace the plastic stem insert & rubber ferrule – job done.