Don't carry an indicator in this area and you will be tested often and not just by your partner. The coaches know it and will repeated ask for the count of the BU from the coach's box.
It's a tool. Humans make errors and it seems that if you are doing the job right, you should have quite a few other things to run through your mind without worrying about the count.
It is not difficult to lose a count, so I believe that every available resource and tool should be used.
Even Uri Geller (?) carries a hammer when he needs to straighten out a nail.
