I am aware of the GPS compass issue. Fortunately, I have a pretty inherent ability to know roughly which direction the 4 points lay, as long as I am outside.
Regarding raising the boom... The cat 25 comes with 2 options, the standard and the tall (I believe the hull is the same). Now, I understand that on the tall rig, you have more sail area, and maybe I am not understanding all the dynamics at work here, but wouldn't using a shorter, standard mainsail on a tall rig with the boom raised, be no different really than sailing with the tall rig with the main reefed?
Or is the difference in dynamic because the boom would be further from the centerline of the hull?