digging under a spire risks destabilising its foundtions potentially.

Could it be possible the spires absorbs the kinetic energy from vibration and use it to power some of its features?

I wonder if it is possible for a giant tree spire, a spire formed from a living tree or formed nearly entirely from wood.

Say wayists have a temple and library in every spire, why would they have not shared such an ancient book with other spires before? And this spire had multiple copies, do we know if the printing press has been made yet. If books are so rare, they might not. So this spire might be where the book was first written.
 Each temple in each spire, likely to have the collective knowledge of that specific spire. I bet that it is possible that every book written publicly and many private ones were in the library.

I doubt they mine near or underneath a spire, they can't risk messing with the foundations. And further away from the spire the more dangerous it is to min it.

Do we know how many spires these mines are said to be supplying, I can under stand limited mining being acceptable for a few, but for larger numbers a powerful monopoly would be formed.

 BOth books and ships are said to havea kind of soul, so i wonder if this is from the wood it is made from. Just like how the silk is special here, wood is important.
 I hope that the destroyed temple library is one day restored and perhaps enlargened. It could a spire wide project, with donations from many rich people. I wonder if hte last two books carry the remains of that developed soul at all.
The trees in this would might have unique properties. I have this idea that Grimm could develop powers similar to the ones Folly and her master have, but insteaad of his being getting holes he fills with madness, he could fill it with his ship. The ship could act like that cane or the collection of tiny crystals Folly has. It would be a perfect focus for gimm, as he hates being away from his ship.
 I can imagine like how the ship tracked the collection, it creates a star for albion and one for mist shark, and other key points. A ship that is never lost, able to point to every spire it has every visted, and track ships even though the thickest mist is invaluable. If it can percieve the ether and the currents, it could sail in almost any condition.
 I am imagining them being magical sips, similar to the live ships from the robin hobb books. They are aware ship with magical powers.
 I wonder what would happen if they started to show those trees in the spire, or simply a bonsai version of them.