I'm not aware of any way to modify the injector timing - this comes from your computer. While there are some devices that can modify the way your computer responds, the injector pulse width is normally driven by values in a table based on the performance desired and known variables relating to your engine and the vehicle specs.
I didn't see pressure regulator mentioned in your lengthy list of repairs? Have you verified the fuel rail pressure? I would place injector timing at the bottom of my list of probable issues. (Unless there's a TSB for this.)Is it hard to change the timing on a fuel injector?
You might want to see if the fuel lines are placed correctly. That can cause your mornings hard starts.
The timing should only be done by your local fuel shop.
