Is there any reason why notarization shouldn't be performed using the copy of `altools` in Transporter.app rather than the one in Xcode? It says it's version 1.1, which is the same as was in Xcode 10.3, although the file is smaller. A quick test here shows it works OK.
(I'm particularly thinking of people signing AppleScript applets, who otherwise have no reason to download the many gigs of Xcode.
