Perhaps I’m figuring things incorrectly – it was about 14 hours total from the time I mixed the dough (around 6:30-ish pm) until the next morning, around 8:30 am, when I scraped the dough out of the bowl for pre-shaping. That includes the one hour of letting everything sit, and the two hours of stretch and folds on the half hour. Temps inside our house are around 67 F, though dropping to 64 F over night.
You are right, though, that sprouted grain is usually more active than non-sprouted. My starter was a little sluggish, and I only use 60 g, but that was probably a good thing in this case. I was up around 6:30 am but the dough didn’t seem ready. Two hours later it was smooth-ish on top with a bit of a dome and lots of bubbles visible through the sides of the glass bowl, ready for the next stage.