Yes, we should be using a circle constant that has a value twice that of "pi". We should not be calling it "tau". That's already used for too many things, and

Yes, we should be using a circle constant that has a value twice that of "pi". We should not be calling it "tau". That's already used for too many things, and anyway the constant is important enough to deserve its own symbol. Instead of cutting it down from two verticals to one, we should add a symbol that has three verticals. Which has the additional advantage of giving a real visual cue to what's going on.