iCloud, Appstore, and proxy servers

We're adopting Macs in our environment and are building a management infrastructure to service them. We utilize configuration profiles delivered by jamf to lock out the iCloud storage. We also have a proxy server that all corporate devices must pass through. At current, this proxy blocks iCloud. As a traditional Microsoft Windows shop, we have partnered with Microsoft and utilize OneDrive.

We would like to continue blocking access to iCloud drive, but by blocking icloud.com it seems that users are not able to download OS updates or apps from the app store.

EDIT: Chose wrong category. Hope this can be moved. If not, I'll resubmit in the proper forum.

Is there a way to allow access to these core iCloud services (app delivery and OS updates) without also granting access to iCloud's cloud storage?

Thanks!