@
aldist,
Blocking the telemetry in Windows 10 is an illusion - it can be only reduced.
SmartScreen Application Reputation is the best-known file reputation service for application installers. It is also the best protection against the 0-day malware (EXE, MSI, ...) executed by the user after downloading the file from the Internet (via web browser and some online services like OneDrive). The SmartScreen telemetry includes the information from MOTW (Mark Of The Web) and information about the file.
How do you recognize that the application installer downloaded from the Internet is safe? VirusTotal will give you too many false positives. The installed AV or on-demand AV scanners are not especially useful for 0-day malware. Online sandbox analyses will give you many false positives and can take much time. Furthermore, they require some special knowledge.
SmartScreen Application Reputation will solve the problem in one second for about 75% of installers. So, you have a big advantage, because your problem is four times smaller. Do you believe that adding default-deny firewall rules can save you?