Canting can change the point of impact for sure, especially if the shelf is a ways above your hand. I tend to cant more when the target is closer and less on more distant shots. Canting on the closer one gets the riser out of my line of sight better. One of the reasons I removed some wood from the right side of my riser was to help me keep the bow aligned where I wanted it on EVERY shot. It probably wasn't more than a 1/16th of an inch, but it was in the right place, hopefully. I had to grind off some of the nice epoxy finish to do it, but I'll finish it with Truoil and blend it in. It may eventually wear a thin leather grip anyway, but I'll have it finished well enough to pass without the leather anyway. Most important to me is that it fits my hand and the arrows land where I want them to. I don't have a lot invested in this bow, but I've never been shy about customizing grips on any bow I like anyway, lol!
Good luck with your tuning. I have some new arrows coming tomorrow, so it will be a new tuning adventure I imagine. Been shooting ICS Bowhunters for years, but I'm trying some GT blems from Big Jim. They are supposed to have the same spine but more mass. I wouldn't mind gaining some mass, but I'm hoping the spine is pretty close. The last GT shafts I tried were awful stiff.