There's a learning curve to straightening shafts, at least for me.
Been at it (building/ maintaining woodies) a few years now. In fact, Dutchman, I've appreciated your own wood arrow build-a-long posts!
But about straightening… using a spin tester of some kind - however simple - has made it a lot easier for me. Also using a compression straightener. As time goes on, it's becoming easier, and more intuitive. Just another aspect of how rewarding it is to learn and grow with our sport and equipment. I now get a lot of satisfaction in getting a troublesome shaft back to a perfectly straight spin, and get a little quicker with it all the time. Knowing when I can give just a little bend by hand, taking a bend out of the fletched section, etc., are now kinda fun.
Big fan of Doug Fir myself, too, as I've noted in several other posts.
Dropping down to low 40's bows, I also use sitka spruce, to keep the arrow weight where I like it.