ok, next update for any CR5 owners interested ...
MODS
Head surface machined .7mm (closed squish to 1.2mm).
Narrowed squishband to 14mm wide (down from 19mm).
Running either Boyeson dual-stage reeds or full-size carbon reed, trimmed-out four of the six ribs in the reed-cage (left the centre ones in for reed petal support).
Tried a DGL carb needle, as many riders suggested it on the web. Too lean at 1/8th throttle and rich at 1/2, so have ordered a CEJ needle to try, will update once tested.
From years of jetting bikes, I live by the rule "where you shift power you must shift fuel", I also just found this with my KX/KDX400, with the mods to improve low-rpm power, I've had to go to larger pilot jets and needles with a smaller diameter straight section.