I ended up using NaOH/CaCO3 (solids) mixture in a beaker filled with sand inside a bucket of water (no water contact obviously just used to stop the glass from cracking from heat). Put it in the bucket of a tractor and lifted it to about 5 feet to duck under during addition, otherwise the liberated gases are more likely to contact you; but at this point the gases should all THEORETICALLY be neutralized, however I wasn't about to go take a whiff to prove it.
Anyway, I searched and searched and basically I think the answer is "the only real, safe way to dispose of BBr3 is to use it in the process it was originally purchased for. So when that process is deemed too hazardous to proceed (as in its a new, unproven process I was pursuing), the BBr3 becomes a big risk and problem to get rid of. My dad said things like "whip it in the woods" "throw it out of the boat while moving" etc., which would be a lot easier and safer to me immediately...but as a chemist i couldn't. NIH said for immediate contact relief use lime which made a lot of sense to me versus my original idea of NaOH as it releases H2O which will react violently with BBr3. But a stronger base I felt was needed in addition, so I used about a 70/30 (CaCO3/NaOH) mixture.
End of the day it all worked out, but made me very uneasy. Steer clear of Boron Tribromide!