Edwards wrote:An 8 speed Shimano compete drive train indexes perfectly with Campag 10 speed at the rear. It is the front that can be a problem due to the different cable pull.
If one of the extra clicks is used at both ends of the shifter range then the inner cable can be properly rested with no stretch at all.
At the front I believe it is only a problem with Shimano road mechs, which need less cable pull, my front Alivio 8 speed MTB mech is absolutely fine with 10 speed Ultrashift Ergos, I get useful trimming (about 3 clicks per chainring I think but must check that) and plenty of range across a triple chainset. I believe you may also get good results using a Shimano flat bar road front mech like an R440 etc., or on a normal road mech you can modify the cable clamp position with something to extend it further from the pivot point.
I am not sure why you would want an extra click at both ends though? Surely it is better if when on the smallest sprocket the mech is positioned by the end stop screw, with the shifter at the fully released position, so that the cable is just slightly slack. This is how I have it at the rear with 10 speed Ergo shifting 8 speed Shimano. With an extra click at that end the cable will be extra slack and prone to snagging or for outer cable being dislodged from the frame stops etc.