Artillery Spells & Felltower

So how will GURPS Magic: Artillery Spells affect DF Felltower?

Much like Death Spells, I'll pick and choose the ones I like. Of those, they will similarly be:

- lost or secret knowledge. You can't just go out and learn them.

- research might reveal what spells exist, but not enough details to enable someone to cast them, even with Wild Talent.

- access to them will be through Felltower. They'll be discovered adventuring, or thanks to adventuring.

- enemies may have access, as appropriate, but generally things will continue as they were before.

I love the book, but its contents will ease into the game as the PCs adventure. The answer in DF is always, it's done through adventuring, not through town.