Interesting! My course instructors yelled at us as we rode by if we had our fingers on the clutch or brakes. We were learning braking and he said I reached for the brakes too early. I knew I had to stop, so I accelerated up into 3rd (around 60kmh) and then when I was 10m back from the cones put my fingers on the lever ready to squeeze as soon as I passed the cones). Not sure why they don't allow this, seeing as motorcycle riding is all about 'anticipating'.
I understand why you would do it, and frankly agree with covering the brakes in city driving opposed to nothing at all.
I can answer this one.
You have to remember in BRC, we are coaching folks who may have never ridden before. Allowing riders to cover front brake when they're riding for the first time is asking for trouble. If handlebar is anything, but square and the rider panics and grabs a handful of brake, down the rider goes!
So when it comes to the quick stop exercise and test, the idea is to pretend you're riding in a straight line with clear view (12 second path) and then something suddenly jumps out in front of you. That moment is when your front wheel crosses the cones.. so until your wheel gets there, we want you to be on the throttle. For BRC, there is no being on the throttle and the brake at the same time, remember? All 4 fingers, all the time.. either brake or throttle, not both.
Why? Again.. because it's aimed at absolute beginners and the theory is it's better to separate the 2 action as much as possible. Less confusion.. less finess required to *succeed*, etc.
Covering the clutch IS actually encouraged, especially on day 1. That's the *safety switch*.
Now.. does this mean you can't cover the brake for the rest of your riding career? Of course not. If you can do it comfortably and practice riding and doing quick stops like this, by all means go ahead. No doubt it will reduce your total stopping distance if your fingers are already on the lever, vs having to reach for it... remember: at 60mph, you travel 88 feet per second. Shave off 1/4 second.. that's over 20 feet off your total stopping distance (theoretically).
Personally, I do not cover the brake unless my rider radar goes off(intersections, busy streets with parked cars, driveways, etc).