I have played with our local ash quite a bit and found it all comes down to early to late ratio.
Some of the stuff I cut that was struggling under a big canopy had loads of real spongy airy early growth and little late which made sense I suppose.
When tillering it seemed to just keep taking set. When working down through the growth rings the early had the consistency of Cheshire cheese. Had two like this recently and gave up as soon as they started to chrystal, very early in tiller too.
The couple i made from the faster grown stuff with large late growth rings was far better.
I was watching a tv program recently about a guy who is trying to make a woodland business work as a coppice and they had a world class furniture maker in who was after ash timber. He dismissed the slow grown stuff with thin rings immediately and went for the opposite. The furniture maker did some very extreme steam bends in his work and knew what he was doing.
In regards to trapping pretty much all of the bows I have made from ash came from small diameter stuff so the shape was there already
Heat never harms white woods