Have you tried changing the 'span' adjuster? if its set on 3 or 4, try it on 2 or even 1 (if your hands are large enough!)
Setting it to 1 produces quite a lot more piston movement and thus a little more clutch dis-engagement than 4.........Try it
I would hesitate to 'adjust' the screw that is glued in place for a good reason! ie. the cylinder has been adjusted on assembly to produce the maximum movement without covering the 'bleed' hole. If the 'bleed' hole is covered, when the fluid expands, it has nowhere to go; on the clutch, at worst it can cause slippage, the same on the front brake can lead to a locked brake..........care!!!!!!!!!!
