Here in this first picture where the zip tie is pointed you'll notice there's a little metal stop tab that's cut off. This allows the body to be the actual stop. When determining throttle travel make sure your cover is on because it will limit it compared to having it off.

Here in the second picture I ground off enough material to get the desired amount of throttle travel. This throttle easily opens a Crankshop 54mm and pretty sure it has enough to do a 56mm.
Removing material allows throttle to close all the way. I used a 4" peanut grinder with a 80 grit flapper wheel to modify the parts.

Hope this helps you out Geno..