Consider adding user-definable hooks or events

[macarie]

It may be helpful for some things.

e.g., it would allow to sync locale status with the server (setLocale -> fetch request automatically).

On the other hand, it's possible to do what the example suggests by exporting the locale store used by adapters. Both Jotai and nanostores allow subscribing to a store's value; in Solid and Vue, the reactive primitives are not bound to components; Svelte?