People getting WAY bent out of shape over that magical mystical 0.065 target. It's just a target, not an absolute. It'll work fine at higher resistances AND be just as accurate (which is to say, just as much in the same ballpark, neither Yihi or Evolv is really what you'd call dead nuts accurate).
It HAS to work just fine and be as accurate. Otherwise, the board wouldn't work after the first hit of power and resistance starts climbing. They've got tables that account for the resistances that equate to temps of 200F to 570F, from the 0.05 ohm minimum to the 0.3 ohm maximum. As long as the baseline resistance is on the money and the coil is in the operating range, nothing else should matter.
That said, they probably recommend that 0.65 because that's an artifact of using thicker (easier to work with) Ni200 with a non-ludicrous amount of wraps. Which is a great thing, it gives the SX350J a lot more flexibility than the DNA40 when it comes to coils and wire gauge.
Getting back to your car analogy regarding titanium (or twisted Kanthal/Ni200 for that matter). To me, it's more like you've fitted tires that are a different profile/size than stock, to improve traction, but you can't re-calibrate your speedometer to give you a precise reading. No big deal, some simple math tells you that 45 indicated is indeed 55 actual...and you're really only worried about not exceeding 55 so there's only one equivalent to memorize. Is it ideal? No, but you've got a hoopty with better performance at the slight cost of doing some mental math.
It's even less of a bummer when you realize that your speedo with the stock tires had a (conservative) margin of error that only worsened as speeds got higher, so precision was already a unicorn.