I THINK, the best starting point is going to be to hoist the main and get the mast curve to fit the luff of the main through a combination of diamond wire tension and spreader rake. Are you running a double spreader rig with single or double diamond wires?

Most of the N20 tuning guides are for the carbon mast; we don't go much above 42 on the Loos gauge on the carbon mast. I'm not saying the aluminum will bust when you go higher than this, but for right now (until someone who's done it chimes in), I would stay below this value.