On the Billy Sheehan signature Yamaha Bass there are additional neck screws that are countersunk and come in at a fairly flat angle and that concept might help.
Agree with Frankie that there is minimal timber both underneath and all around the neck pocket. I would be adding something, possibly Plasti Bond if they still make it as that stuff is really strong and can be easily shaped and sanded once allowed to fully cure. Have done this sort of thing when helping my Dad out with repairs to sailing boats when I was a kid (last century).

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