Eh. I never saw a problem with Pi, and despite having read up on this 2pi thing before, I just don't see the point. It strikes me very much as a case of better-cause-it's-new, created for the sake of having created it rather than to fill a genuine need. And the idea of a campaign to replace the historically used alternative with it, calling it wrong (despite being no less mathematically accurate), just seems very much like a thing

I'm thinking on reflection Tau is probably a Free Council wheeze. Pi doesn't feel convaluted or unhelpful enough to be any kind of Seer plot though, really.