Batch Update
Fermentation in my BB batch finally took off a few days ago. Yesterday morning the SG was ~1.015. I pulled and drained the fruit bag and let the batch sit undisturbed for about 14 hours. Last night, I racked it into a 6-gallon carboy and airlocked. This morning the airlock is really busy, about one burp per second. I'd expected some foaming (hence the oversize carboy), and indeed there is at least an inch of foam now.