Yes, brazing material would be softer, but would still make the drill walk away from anything inside the original hole diameter. And you still have the problem of getting a drill to put the right size hole for the proper press fit of the bushing.
The bushing by itself might deform too easily where it would be unsupported at the notch, so filling with epoxy material would be my choice, just to give the bushing a bit more backup. When suspension is concerned, it's better to have suspenders along with the belt.
