Had two more sailng sessions, first a chance to try my 5.4 cammed sail. With winds of about 12mph this went well and outsailed a similar yacht rigged with my cut 6m, only real issue was getting the c of e further back meant that I had very little headroom and restricted visability, add to that a milky bottom panel. Second session was back on the runway, 18mph plus gusts, flew my 4.1 sail on a new mast since last time, a much better feel straight away softer mast was more forgiving with wheel lift a lot more controllable. Up wind performance was good, down wind poor, easing the outhaul improved things significantly but if the wind dropped the sail lost shape and power.
More work to be done then. I would like to get the mast step further back so it's an angle grinder job again as for sail tuning I am considering thinning of the battens in the uncammed sail to get more shape, this was an improvement I found successful on my cut sails, what's the thoughts? The other mod under consideration would be to slightly shorten the batten pockets to help them pop round the mast?????

un cammed windsurf sails (most of them ) are designed to depower when sheeted out,ie when turning on the top of a wave,so that control is not an issue,they do depower as soon as the wind drops mimicking the rider sheeting out.Dont think thinning the battens will help could make it worse. That's why race sails were developed with cams so that the shape was maintained through out a wide wind range. If you have spare battens then worth a try ,but don't expect too much//. good luck