So, on the desert ironwood, generally speaking, for people who may be interested in using that material for a Pinch . .. .
I wouldn't say, yet, that this material is a sure bet, and I'll tell you why. I had two pieces in the shop for this batch, and only one seemed a viable candidate. The main difference being that the "good" one was a burl, whereas the one that was too iffy was straight-grain. The sum total of my experience is in these two pieces of wood; so it ain't much and I'll try not to generalize. I found that the straight-grain piece was weak in the adhesion between the wood fibers (so, prone to cracking, checking, splitting, snapping). It's a very hard wood that proves delicate/fragile on this small but demanding scale of "mod". Not so much in the glasslike/brittle category as the splitty/cracky category.
And/but/so if the grain pattern is chaotic, then there aren't distinct lines of this weakness (as in all lined up, shoulder to shoulder, and pointing in the same direction). Also, the burl seems to be almost a "compression", wherein the chaotic fibers are tightly bound together, and there's not so much of that roomy "in-between" space. And this is true of a lot of the woods we use. The burl seems always stronger and more tenacious, and not weak in any one particular plane.
Another characteristic that I noticed while working with this wood was that, on a very small wee scale (not microscopic, but tiny), when machined to a very crisp edge or corner, it seemed a bit crumbley/flakey betimes. That weakness only presented on a sand-grain level/size, and the issue disappeared with the lightest easing of the edge. So, I'm hopeful that this characteristic is lost in the larger mass of the wood (that weensy crumbles don't translate to anything in the physics of the normal scale). My gut tells me it's limited to the world of gnats' ninnies. Kind of like how the strength of an atomic bond means nothing to a sledge hammer and a plate of butter in August. (only . . . switch it around . .. . see?

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For me, I'd really like to see specific Ironwood Burls before someone buys to send to me. From what I've seen, the distinction (how it grows) between "burl" → "figured" → "straight" isn't clear cut.
For y'all, I would treat this as a bit of a question mark, and a bit of a risk until we've put some track time on a couple mods. The reason we went ahead with this one mod is because it seems, in all likelihood, that it will be a winner. But still, I can't say for sure.
Lastly, another factor that I have to hold off on speaking to until tomorrow is stabilization. The piece we used for Rattler's mod was labeled as "stabilized". However, when I go back and look at the source, I'm not seeing that distinction made (yea or nay) on any of the other pieces. So, I'll call them tomorrow and confirm. IF this piece was stabilized, it would be another factor that may/would have contributed to its viability. If it was labelled "stabilized" by error, we needn't concern ourselves with that as a precondition for shopping Ironwood.