Man, Strange will be all over that book about the fae like white on rice.

And yeah, Strange will happily talk shop/help Foster out with magic/etc. They've actually got halfway decent cr in the first place (especially halfway decent by Foster standards) and Strange has actually gained a smidge of patience due to his canon update back in Greysol, so we'll see what happens!

and don't worry dude, Childermass is heckin cool, it's okay that ya can't do what he does, Strange can't do it either.