So looks like the strait jig can get me a slight rotation. I couldn't find in the Ashby where they talked about feather height and spin on the arrow. Doesn't mean it's not there, I didn't re read the whole report. I emailed the ol RF and he said Ashby "believed" some rotation was good. To much slowed down the arrow, and if your arrow flight is perfect, there is no need to correct it.
I did pick up again where having the broadheads and collar bigger than the arrow can add up to 30% in penatration. So going to a smaller arrows is not a bad thing. I had in my mind it was less structural integrity. But if it's build well it will hold up.
I don't believe that Ashby ever talked about an A&A fletch in his reports. But he does talk about them in several podcasts. Keep in mind that these arrow lethality studies are an on-going study. The Ashby reports are older and may not entirely reflect his current beliefs on arrow building.
One of the core principles of the whole system is to have a well tuned bare shaft before you consider fletching. Ashby talks about his guys shooting 3D courses with bare shafts. He insists that a well tuned arrow really doesn't need fletching when shooting field points. But fletching IS a requirement for broadheads. The configuration of the fletching depends on some other factors. Arrow tuning, broadhead size (head SIZE, not weight) FOC, shaft material all come into play when you determine what fletch you will need.
His point is to use the least amount of fletch you need to stabilize a broadhead. A well tuned arrow should guide a broadhead with no helical or off set. Not saying that nobody should ever use helical or off set, but if you can achieve stable flight with a straight fletch you are better off.
One of the benefits to the straight fletch is quieter flight. A quiet bow (which is helped with a heavy arrow) and a quiet arrow flight will be less alarming to deer just prior to arrow contact. Helical feathers stabilize better but they are louder in flight. A well tuned arrow with adequate size fletch is quiet and does not need helical or off set.
Rotation in flight will occur due to the nature of a feather. Feathers are not equal on both sides of the feather. As air passes over them, lateral air pressure is created. That causes rotation. If a higher rate of rotation is needed to stabilize the arrow, then there may be other approaches to improve the arrow build.
These small diameter shafts are a little problematic when trying to fletch off set or helical. Those old fat arrows ate much easier to attach angled feathers.
Last point...in flight rotation does not contribute to rotation during penetration of single bevel heads. The bevel is what creates internal rotation and bone splitting. I contacted the Ashby foundation about that. I wondered if rotational momentum in flight transferred to increased action of the single bevel. Their answer was that it did not.