So after having the BOB for a while I noticed I don't like pushing it with the infant seat adapter. I know I am supposed to use it until Addie is 6 months, but I haven't really been on rough terrain yet. I've only ran paved trails, and when I have "off-roaded" with it, Addie wasn't with me. I found a way for her to comfortably sit in the seat while I am walking on a paved trail without using the infant seat adapter. I DO NOT SUGGEST doing this if you are running (even on paved roads), but this quick fix came in handy at the park when Addie wanted to lay down but not be in her car seat.
I took an infant insert/ headrest that fits in her carseat, and put it in her seat in the BOB, with a receiving blanket rolled up, around it, and she fit snug as a bug. Her head was not moving anywhere! Again, the manual does not condone my behavior, but it worked for me, and if you have an unruly infant who just wants to lay down in the stroller, this might work for you.
Here is a closer look:
The specific infant carseat headrest I used wast the Boppy Infant and Toddle Head Support. (Click for pricing and ratings). As you can see she's pretty content. They both stayed like that the whole way back to the hotel.