I was pleasantly surprised that *some* things worked in attempting to export stuff out of tilt brush. Still no luck bringing the fbx into threejs though – but the fault, as always, lies with threejs. Seems that the actual fbx is solid (and fwiw the sketchfab people are doing a fine job translating it to webgl).
Also spent time fighting with the fractalicio.us tweetbot, to no avail. Not every day is a winner.