You could remove a little material from the opening drum surface on the original throttle tube but for it to be correct, that same amount of material should be added to the return side of the drum to maintain even cable slack as the throttle is opened. Also I believe a throttle tamer not only initially opens the throttle slower but actually opens the throttle faster as throttle travel approaches full throttle (WOT). That way it alters the way the throttle is opened while keeping the total throttle travel the same as stock.
Brian
That is an interesting thought, but I think unnecessary. I suspect the amount of slack introduced to the decelerator cable by a slight change in initial ramp angle of the accelerator cable would not be enough to warrant adding any material to the guide slot of the decelerator cable.
It probably would affect how the throttle cable adjustment procedure was done though, meaning you would need to leave a little slack in the decelerator cable when fully closed, as the two cables would be fighting each other once the throttle was opened past the point that was modified.
Something to think about I guess.
As for the change in ramp rate at later throttle opening, I'll have to check into that too. I don't mind the stock opening rate, just the light switch response from full closed to when you first crack the throttle. To be honest, I still think it's a miss-adjustment with the TPS, which may be cured by a very attentive TB sync.