to do a bit of answering my own question ..

After a particularly good 30kn catapult I trashed my dakine speed seat and bought a new prolimits seat harness. All of a sudden things clicked - no spin out, could get the front leg out straight easier, load up the fin better, board trim sooo much better. My assessment - the prolimit has the hook really low, the dakine was too big for me and always rode up (chest harness height) - thought I had harness commitment, obviously didn't! Happy camper

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