AcraGlass is a wonderful product, I love it, believe in it, and use it on all my flintlocks! On bows...not so much.
You could drill out the knot and fill with acraglass, but that doesn't change the fact that the wood around the knot has really swirly grain and as it's a board those grain violations are deal breakers! If it was a stave, you could chase a growth ring and avoid all kinds of problems. But once those growth rings have been violated the bow is already broken, you just haven't finished the breakage.
It is possible to sinew the bow, but that's like putting a $20,000 paintjob on a 1973 Chevy Vega thinking it's going to go faster. Finish it as a wallhanger and start a new bow. George Tsoukalas has a website that shows quite a few tips and tricks for board bows. I've done probably 75 board bows and still learn from Jawge's experience. For about $7-10 you can get a good red oak board at a Home Depot/Lowes/Menards store and turn out a bow worthy of packing into the interior of Alaska for that hunt of a lifetime.
To quote Red Green, prophet and guru to the real men, we're all pulling for you! Don't quit now, you are learning!