What are the IP ranges of Apple's privacy protection proxies?

When Apple users allow the settings

• Maintain General Location allows sites to show you localized content in Safari, while your IP address stays hidden
• Use Country and Time Zone uses a broader location for your IP address, still within your country and time zone

Apple currently publishes the IP-address ranges they use (for the purpose of populating Geo-IP databases) on their API here:

https://mask-api.icloud.com/egress-ip-ranges.csv

(Source: https://developer.apple.com/support/prepare-your-network-for-icloud-private-relay)

To prevent users in your network from using Apple's privacy protection proxies Apple does not publish the IP-address ranges in use (as far as I know) and instead they recommend:

The fastest and most reliable way to alert users is to return either a "no error no answer" response or an NXDOMAIN response from your network’s DNS resolver, preventing DNS resolution for the following hostnames used by Private Relay traffic.

and block in your DNS

• mask.icloud.com
• mask-h2.icloud.com