Just follow the grain around that knot and u can narrow it quite a bit, most of the na bows were 3/4" wide at the tips,
I'm with Bubby, and George T. ERC is a very lightweight wood, so a little extra wood at the tip isn't going to kill you. Draw lines to where you would narrow the tips, if the knot wasn't there. Then, measure how wide the knot is, and add that much width total in a circle around the knot, and blend the circle lines into the straight lines.
ERC is wonderful stuff, but junipers have a reputation for being a litle tension weak on the back.