I've found two problems that will affect a lot of users.

1) The Microsoft Symbols server msdl.microsoft.com is blocked, this host may be used for more than just Symbol downloading, but I could not use Windows Debugger at all when Beacon added IP blocks to Windows Firewall.

2) Google Hangouts as of last night could not successfully make a call, I thought the service was down all night, disabled the Beacon Windows Firewall rule and tada it started working again.

You may want to make a list of warnings to show users when you block such a large range of IP addresses, some which don't even appear to be MSFT ones!