That's pretty neat! Ice boats are discussed a lot in Frank Bethwaite's "High Performance Sailing" book...he reckons them to be the highest performance sailing craft. At thier typical speeds (3-5 times true wind velocity are possible), apparent wind is basically always from directly ahead. This has significant impact on rig design for these things relative to "soft-water" sailing. Perhaps the lee-bend mast only has benefits at these higher velocities and would prove detrimental at slower speeds and higher angles to the apparent winds in which we cat sailors spend our time.