I've made a few through the years. I ticket to haveing them stay straight is just let them season a couple years. Age helps out with any shoot shafts staying straight. I take the time to really straighten then bundle tight. I like to use duck tap. Just put them up where the can lay flat and forget about them. I don't make any arrows unless the shoots have seasoned for 3 or 4 years. I have some shoots thats nreally nice. I'll debark and restraighten after 2 years then let them season a couple more. If I get the time.
Doing this I've never have any trouble with shoots staying straight no matter the type.