I know a spellbook and a formula book are very different things, with magic being separate from alchemy, but I'm wondering, can you use one book for both formula and spells?
I don't see any reason why not, at least for home games. There doesn't seem to be anything particularly special about the books themselves, other than the fact that they're called out as separate items and not just 'books'. Society play might be more strict about that sort of thing.
Mostly asking for Society play. I'm already planning on Hefty Hauler, so im already covered strength-wise when i hit level 2, so it doesnt matter too too much, just trying to figure it out.