That's also the way I read it, and indeed both WebSQL and IndexedDB only have async interfaces. IndexedDB used to have a sync interface available inside workers, but that was removed from the spec as there weren't any supporting use cases.
Overall localForage seems like a better cross-browser storage system, it also has a pluggable backend system (drivers) but defines an async interface.
Duh, of course! Sorry, 3am and not too sharp in the nut at the time :)
I'm genuinely interested in supporting every needed use case - would you be up for creating an issue? Either way I'll have it in the back of my head and see what can be done.