I've got 1mm more lift in my GS1000.
My experience is, use the stock timing, everything else creates a poorer / sluggish throttle respomse, and on boost there's no / hardly any difference.
What I also know from experience; Say, the GS1000 with "hot" (284 dgrees IIRC) cams won't work on a stock CR, it makes it actually slower/sluggish.
How this works with a turbo I have no idea, but probably not well.
So, probably best, keep it stock, or close to.