What I would do, and this could be really bad info. Anyway here it goes. I would take off the entire backing strip, sand the back lightly to remove all the glue, and backing. Do the Urac thinned or the super glue trick to solidify the crack. After that dries, I would then sand it for another backing strip. I would then put on a hickory backing strip, file it a little closer to the edge, to cover the crack better. Then just go back to retillering the bow, but I wouldn't shoot for a real high draw weight. Maybe around #45.
Thats my way. Not sure its the right way.
Bill