I'm not entirely sure if the web shield doesn't already give a warning of file reputation. But possibly not as that would need to reference the avast cloud for that, which could slow web browsing a little.
I have mentioned in your other topic that you can exclude a file, but not the actions it takes. This is further complicated in that the web shield exclusions are web site related. not file or process related.
Remember, you still have the file system shield as an additional resource and that with the Hardened Mode enabled as you have should notify that file-rep warning.