I apologize for a bit of forgetfulness that I've discovered.
The CCS 5.25" formats do indeed reserve 3 cylinders (6 tracks) for boot and
the 8" does use 2 cylinders/4 tracks. These were 20-old notes and I'd
forgotten that I long ago changed the way I thought about boot information
(in my current data, it's all noted in terms of sector
count+density+interleave+skew). Sometimes one forgets.
Cheers,
Chuck