It won't be much of a surprise to folks, but I figured I would report that the B9 Cherry/FormLabs White version of the mix works nicely, too. I did 50/50. Still very red, no sign of the white making it pink. First prints with the mix failed, I think because I jumped the gun and started printing while the mix was still de-bubbling from my stirring, and I also didn't scrape the silicone with the scraper. After four hours of de-bubbling (while the first attempt finished the 1 of 3 parts that actually stuck to the build platform), the second run worked very nicely. I don't have a picture yet, but sharp outside corners are way better.
I concur that this mix comes off the build platform easier, as Monger mentioned in another post.
And for folks interested in mechanical models and not just art/jewelry, it seems this mix is not as stiff and maybe less prone to fracture than the straight white, even after curing in the sun long enough to get rid of all surface tackiness.