Dan, "The arrows always flew like darts with fletch and would drive BHs spot on"
I'm not either....Broadheads and field tips flew like darts?....Ok, What if the BH's grouped to the left of the field tips??? Their stiff, right?...Same with bare shafts...You are/were looking at the wrong data. "But they still show stiff" What about them told you they were "stiff"? Shaft angle I'd bet so you are mixing methods that work with those that don't. I'd bet Fred did the same with BH's...And it's the same as the correct way to bare shaft.
I seldom if ever bare shaft tune, I use wide broadheads. But for those that don't want to spend a $100 on an assortment of BH's to tune with, bare shaft planing will tell you what you need before you buy. I wouldn't strip fletching off something to bare shaft, again I'd use wide broadheads. If I was setting up a bow for 3D or other target work and never intended to shoot broadheads, then I'd use the planing method. Because there is no better way. Again you can't say one works and one doesn't cause they are the same thing. Canting? Sure, you cant the bow 20 degrees it'll twist the groups 20 degrees? If someone can't in there mind twist the groups the same as their bow cant, I'd not sure there's much hope!
Once tuned, canting makes no difference....O.L.