Arm out the Window,
Make it anything you like I guess.
BROC in my mind is a good stable speed, and one you are likely to be close to prior to landing or setting up for a recce. It also stands to reason that minor deviations from this speed will not have a huge effect on the power required.
The main point is rather than not have anything to work with until someone tells you some numbers, and/or then blindly use them, think about what you can do to become a safer or more aware pilot.