I have been trying different arrows I have laying around in my long bow build and can't get anything to fly. Today I remembered Stu Miller's calculator and started plugging in the numbers. Wow, I am way off. My goal is to shoot the same arrows with all trad bows. To get my new board bow to shoot my current arrows, I am going to need to do a little more cutting. The strike plate position is the main problem. oh well, lesson learned. I have league tonight, so I better get busy.
That's one thing that I've noticed with my selfbow longbows is that they are a different animal than my recurve with the large cut out. I've actually gotten better arrow flight with the longbows when I shoot off my knuckle, but I do like just a tad bit of a small cut or notch in the handle area as an indicator for consistent arrow placement. I don't consider myself to be a really good shot by any means, I'm somewhere in the middle of the road so any little bit helps.
Your going to probably find out that most of your arrow tuning for the selfbows will be more trial and error than being able to rely on a calculated process. Reason being in my opinion is they are going to have to bend around the side of the bow more so than with any other bow. Read up on archer's paradox. It will explain more about that.
Whatever helps you to get that paradox of the arrow bending around the handle of the bow, whether it's heavier tips or lighter spine.....that's just what you'll have to do. I also doubt that one arrow spine/tip wt. configuration is going to work with every bow you build. Unless they are all cookie cutter bows exactly the same length, poundage, length of pull, ect. Lots of variables change from one bow to another.
Don't know if that helps you much, but that's just been my experience.