That’s very unfortunate and strange (considering it’s stabilized) on a beautiful piece of work.
I always install a limb pad liner, often several layers, using it as an opportunity to add additional accents.
I would tape the side cracks to prevent outflow, mill open the crack on the pad top a very small amount (just enough to pool the glue), and pour in some extra thin CA. It’s as thin or thinner than water. It will penetrate right through to the sides and bottom. Then pull the alignment pins, sand the limb pad, and add on a liner, the G10 would work great. If you shape the liner to match the limb pad and the limb butt end exactly, you may get away with not having to refinish the entire riser. Judging by the quality of work you do, it should work out beautifully.
Attached is a picture of a similar piece of figured Claro Walnut with grain also sweeping up into the limb pad, and the liner .
Best luck!
Regards, Noah