Wouldn’t it be reasonable for AVAST! in exceptions category by default include the DATA folder? Or at least MOVED, CHEST folders? 
Personally I don’t think so.
The chest isn’t included in scans, the Moved and Data folders are just regular folders (and can be infected), personally I can’t see any reason to send a file to the moved folder if you can send it to the chest.
The moved folder I believe was there because previously it wasn’t possible to send a file to the chest during a boot scan (as windows wasn’t running), this has now been changed and is now possible to send infected files to the chest during a boot scan (for those OSes that can do a boot scan).
Data folder: no. A virus could infect avast folder itself…
Moved folder: I agree with you… but, won’t be the user in danger if it execute a virus at that folder?
Chest: it’s not necessary. Files are protected (encrypted) and the infection can’t go out from there.