I rely on the bare shaft planing method. I only utilize the bare shaft method when verifying at close range that my shaft spline is not in left field. I only pay attention to the bare shaft mark relative to the fletched shaft.
Often times, I foregoe the bare shaft planing method and go straight to broadhead tuning. Broadhead flight is the primacy of tuning. A bare shaft tuned arrow at twenty yards does not negate the broadhead tuning verification. Have had bareshaft tuned arrows that would consistantly, over a week, tune seemingly spot-on at 20 yards. Shoot the BH and the broadhead would consistently mark 4"s right at 20 yards....lowered the brace height approximately 3/16"s, and then the bare shaft, fletched shaft and BH tipped fletched shaft shared the same mark.
Don't know the min distance for bare shaft plane tuning to have a much more certain BH tune. But bare shaft plane tuning, at 40 yards, has consistantly yielded excellent BH flight and also, shoots holes thru paper.