Those are also prone to warpage in the field.When I was trying to find the profile for my shafts I turned one shaft like it was claimed Earl was playing with, sixteen inches of straight cylinder from the tip. I took it to Buff's to try. It flexed right where the taper went from zero to a mild taper, no flex closer to the tip. Crappiest shaft I have ever shot with. Hard to imagine how bad it was if you haven't tried one like it. Heads turned at the loud snap before I put it in the garbage can. I didn't want anyone to fish it out and have my name attached to that shaft.
The slight rise you mention works great. No rise sucks!
Hu
And prone to chatter in the taper machine.
Imo all shafts should have at least a mm of rise to the middle .