Well, more or less. At 5 am, with ▲10 beginning to bend, the burners began to lose pressure. I feel pretty confident that it was enough, as most of my glazes will go at ▲9, and these had the additional nudge of 5 lbs of baking soda and soda ash; plus a 1/2 pound of salt for good measure.
So, good news and bad: the good news: well obviously. Also, the kiln appeared to be pretty even and easy to keep in a deep or light reduction. The bad news: this was a crazy-long firing, 15 hours, and in the end the cone did not entirely fall. (It still might have done; the gauges read that the burners were losing pressure, but the difference was undetectable just by observing the flames.) 15 hours is unacceptable, of course, but it now just seems like a matter of tweaking. Another foot or two on the stack, and proceed more quickly in the early bit of the firing, or...any other suggstions?
I plan to spend most of today in bed, reading The Physics of Superheroes. Unloading will be Saturday, photos Sunday, if all goes well.