Hi there. Welcome to the boards!
BW recommends waking babies if they nap too long in order to set their internal clocks. The exception would be if your baby seems extra tired, has a rough night, etc and you feel she needs the extra sleep--you'll develop a "mommy instinct" that tells you when she needs the extra sleep more than she needs to be woken up (not to confuse you more!)
At her age she could do a 3 hour EASY, so no need to wake at the 2.5 hour point. The reference to waking a baby after 10 minutes to start EASY again refers to a short nap--if your baby wakes 45 minutes into what should be a 1.5 hour nap, Traci recommends trying to get them back to sleep for the remainder of the nap period, and then waking them for the next feed even if they have only been asleep a short time (for example, 10 minutes).
At your los age we did a loose EASY and tried, as you say, to mainly just follow the EASY cycle. Our EASY ranged from 2.5 to 3.5 hours. And cluster feeding is an optional thing, it doesn't work out for everyone.
Hope this helps!