B⃦ is itself a single character, even if comprised of two codepoints.
It's also the same character the forum is using a webfont to render in BTC.
Using multiple codepoints for a single character is not new.
I am now on a completely different computer than yesterday. Your B-Box now shows up as a B with two feet.
I have also had a look at your B-Box via Chrome on a GNex with Jelly Bean. Your B-Box there shows up as a B. Just a B.