My answer doesn't answer a bit - don't delete the format extension. If you use a specific <format>assembly descriptor to create an artifact (zip, tar.gz, etc.), there is no reason to remove the extension from the file. If I am a user of your software and download this binary, I don’t want to guess what the type of packaging is, I have to say just by looking at the file name.
FWIW, setting appendAssemblyId to false, means that <id>your assembly descriptor will not be included in your file name.
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