SOS – Save Our Space
It’s not only on an iOS device that you might want to restrict the range of applications that can access your iCloud Drive storage space – OS X offers the same options. You’ll find them in the iCloud pane of System Preferences. Click Options beside iCloud Drive, and in the Documents tab you can uncheck apps to block their access. Note that this doesn’t stop you manually browsing to and saving documents to iCloud Drive, but it stops apps saving other data to it behind the scenes.
This might seem like a strange thing to do on the Mac where you won’t normally be connecting over a mobile network, but two primary considerations still apply here. First, in some rural areas the only practical option for getting online at a decent speed is satellite broadband which, as with roaming abroad, often comes with a lower data limit. Second, your iCloud Drive space is limited, so you might want to stop non-essential apps using it.
There is a third consideration, however, which is to use an iPhone as a personal hotspot. In this instance you almost certainly want to keep a handle on how much data you’re using.