But none of that should be necessary. Caches should be managed by the system. If they get too big the system should empty some of it.
Giving the user a prompt is a bandaid on the OS failing to do its job.
Giving the user a prompt is a bandaid on the OS failing to do its job.
Or you could provide a feature like iOS where unused apps are unloaded automatically (if enabled).
But the user should never have to manually manage cache space.