The video does show the arrow-maker heating the entire shaft, and the shaft looks dark, but I wonder if he is just saving time by heating the whole arrow and straightening all bends at the same time. I guess he could be tempering the shafts as well.
IMO, Tempering seems like it might be a good idea for some types of flimsy bamboo (?), but I have some questions about the whole idea of tempering cane or reed:
1. When heating cane (and especially reed) if the thin outer layer gets too hot, it lifts, bubbles, and peels off. I wonder if the cane will be heated enough to be tempered without "toasting" the outer skin of the cane. Also, I wonder if it would be more effective to just heat all the canes in an oven, at the same time, where you can control the temperature better.
2. How do you control the effect of tempering on arrow spine? Do you let the shafts cool and rehydrate...and then check for spine? What if the spine is too stiff? "Oops, there goes another arrow". Or what if the spine is too flexible? "Darn, now I got to heat it up again and wait another day to check this shaft". Seems like an unnecessary hassle.