Understood. I've just been doing it for years. I do tap the front to let others know when I'm going to brake. The only time I really use the rear brake is when tail braking when riding hard at the track which I haven't done with the fz yet as I've only had it a little while. I'm more likely to get ticketed for the integrated head and tail lightsSome states require both brake lights to function independently. Take your chances there.
If he's going the other way in the twisties, either A) he's already determined you were speeding, and he'll turn around and chase you down, so it doesn't matter if you tap your rear brake to slow down, or B) he didn't think you were speeding, in which case it's not necessary to slow down.
Either way, he's unlikely to be able to see your brake light go on in his mirror, and even if he did see it flash he's already made up his mind as to how fast you appeared to be going. Do you really think a cop going by would think to himself, "Yeah, he looks fine. No, wait! His brake light just went on... He must have been speeding! Let's get him!"
Seriously, J., if you're so far over the speed limit on the freeway that you have to use the brakes to slow down to legal speed, he's already got you. Your natural instinct is going to be to roll off the throttle anyway (face it, we all do that when we see a cop), and that should be enough to get you down to legal speed without making a spectacle of yourself. I highly doubt your brake light is going to be the catalyst that causes the cop to pull you over, when he wouldn't have otherwise.
My point here is, this is one of those well-aged myths that has no basis in reality (kinda like "loud pipes save lives", and "don't use the front brake or you'll go over the handlebars"). Removing safety equipment because you think it might save you a speeding ticket isn't a good idea. If you ever saw a cop on the road and he didn't pull you over after you stomped on your unlit rear brake, he wasn't going to pull you over anyway. (Maybe LouG can chime in here with his take from his years on a patrol bike...)
On the other hand, having a rear brake light can be very handy when someone is tailgating you, for instance. You can lightly tap the rear brake and show them the light without actually slowing noticeably. This can be useful when you know you have a turn coming up, or when you see traffic slowing ahead and you want them to be aware, but you don't want them running you over as soon as you squeeze your front brake. I use this technique quite often. The benefits of a rear brake light far outweigh any perceived drawbacks. Please consider keeping it functional...