But the rake of the rudders doesn't balance the helm, just makes it feel like its balanced, right?
True - but compared to the alternative of moving the daggerboard trunks....
No catamaran is balanced so there is no load on the rudders - all rudders carry a bit of the side loading. The I20 carries a tremendous load on the rudders and you can stall them by sheeting the main too quickly after gusts and before the water flow over the foils is at a peak. I've seen plenty of rudders break just from the typical sailing side loads incurred on a 20 yet it feels balanced.
I don't know how much load is good load, but the rudders really do carry a lot more than you would think.
