Quite often when driving I will dab the brake pedal once or a few times when regening in traffic just to ensure that the car behind (often close behind in heavy motorway traffic) understands I am slowing.
You are a smart driver, Andrew!
Over the past 20 years of driving my manual transmission, I remember my car insurance company making a general recommendation that drivers avoid compression braking and instead use their brake pedal so that drivers behind will be alerted. You see, the insurance companies aren't worried about impeding the high-speed flow of freeway traffic, they're primarily concerned with preventing their customers from being rear-ended. It wasn't entirely comfortable, but I have made a point of using both feet when I want to ensure that other drivers won't make a mistake at my expense.
Someone pointed out that you can't flash the brake light with the brake pedal if the accelerator has already lit up the brake light. However, if you use both feet you can hold the accelerator steady enough that the brake light will not stay on, and then your brake pedal will control the brake light.
I guess it depends upon whether you assume that people behind you are better drivers or worse drivers. If you assume that they're worse, then you're safer giving them a few false alarms rather than have them plow into you because they don't slow down when you slow down. For those who are happy assuming that the drivers behind are better drivers than you are, then I can understand your complaint in that light.
Besides, we already have tons of drivers who use their brake pedal as a foot rest, and thus their brake light flickers like bad Christmas tree wiring. I think Roadsters are not nearly that annoying (but I haven't followed one yet).
By the way, Very Orange makes it easy to see the brake lights. As soon as I realized what was distracting me, I used the reflection to learn about the behavior of the brake lights. In my opinion, they work quite well.