You don't even need to do all that, just use
https://robwu.nl/crxviewer/
and insert the URL of the extension, for example https://addons.mozilla.org/en-US/firefox/addon/decentraleyes... .
and insert the URL of the extension, for example https://addons.mozilla.org/en-US/firefox/addon/decentraleyes... .
Should they choose to, nothing stops the site you've linked from masking malicious tidbits in code you request.