Looking at the grain that you revealed in the floor of the neck pocket; I wonder if it might be prudent to bond some sort of reinforcing layer to the neck pocket. This would be like a shim except that it is bonded to the parent body to prevent microfractures from joining up and causing problems down the line.
When you hear musicians talk about breaking in a new stringed instrument they sometimes speak of the wood grain "opening up". This is said to add to the instrument's characteristic tone and possibly to its individuality of tone.
While I don't fully understand what goes on, I'd guess that vibrations in the wood (from the strings) act over time to resolve stresses within the wood by causing microfractures. I'd expect all wooden instruments to be subject to this phenomenon (if it exists) but some might be more prone to suffer damage from it.
Then again, I may just be making it all up...