Damn!

The patch on the Yew heartwood primitive is fine, but as I took it to full draw I heard the dreaded "TIC" It took a few moments to find the culprit, a little further towards the grip another crack has appeared.
The bow didn't explode, so I'll maybe patch it and rawhide back it... or stick random bits of Yew sapwood all over the back (joke). Anyhow, it's not of deliverable quality now, but its taught me why we leave the sapwood on Yew bows and confirmed the received wisdom.
The secod pic shows how much I had to rasp out (and then sand on the end nose of the belt sander) to get down past the crack.
Pride comes before a fall and all that stuff. I'm a tad disgruntled, but I'm always happy to learn, much better to try it and see what happens than to just be another armchair expert.

Meanwhile on the 80# spliced Yew longbow I spent yesterday afternoon steaming out some of the deflex from each limb. It's a really nice shape now and I can see if the outers are moving now without the confusion of the deflex. I'll add some more pics later.