[T77911S]

here is the thing with CP's
you can set the CP anywhere you really want and make it run.,
if you lower the CP and make it richer you will just compensate for that extra fuel with the mixture adjustment and set it back to where it was.
I have done this with my 930. I have set CP's +- 1 bar from spec. AFR's were always the same,

here IS the problem with doing this.
the AFM cone has "steps" in it. there is a section for idle, mid range RPM and then hi RPM.
when you change the CP you change where the sensor plate is for any given RPM.
lets say 4000RPM.
with a lower CP the sensor plate will be higher in the AFM cone than it was at a higher RPM.
the reason I chose 4k is that is about where the shape of the AFM cone changes to make the mixture richer for high RPM running.
now if you lowered the CP instead of the mixture getting richer at 4k it may be getting richer at 3500.

CIS is a great system as far as simplicity and reliability but you really cant tune it unless you actually send your FD off and have it modified.

when I changed my CP on my 930 I could see the different RPM's where it would go leaner for mid RPM cruise.

some people raise their SP trying to get more fuel, it doesn't work. this is more complicated due to differential pressures in the upper and lower chambers.