So, after looking up a bajillion threads (because it's so hard to find contact info for EA Help), I finally found out that they finally fixed the no-BBCode-in-signature problem...in July 2015. Up until then, my signature read:
9/24/14: EA tells me it'll be 2-3 weeks till I can have a BBCode-enabled sig.
So it took only an extra 9 months, plus some more digging through the forum, but I have a sig now. Yeehaw.