Gato, have you measured the bend of your carbon mast yet? Any comparisons with an equivalent aluminium mast?
Ncik designed bend numbers with mast supported at step and hounds were:
10kg at head.
38.3mm fore-aft deflection
114mm side deflection
10kg midway between supports
16.4mm fore-aft
49mm side ways
From memory Gato nailed the transverse numbers, but ended up a little stiffer longitudinally due to his double barrel sail track.
I kept the rig reasonably soft sideways to help it lay off a little in gusts to auto-depower, however, from Gato's experience I believe we could get away with a little more stiffness. I've been meaning to re-engineer to remove the spreaders but payed work keeps getting in the way.