I wouldn't drill through the glass. I think that would lead to cracking in such a high stress area. I think, { NOTICE I SAID THINK} I would drill the entrance from the sides of the limb and pressure feed the glue from a syringe. I just have the sense that going through the glass will lead to longitudinal cracks in the glass. Never a good thing.
Apex,
I know what you mean about a bowyers eye developing an ability to find flaws.
pete