Is there any legitimate reason to minify code for extensions? The size gains are minimal since it's a one time thing. But I agree that it would be hard to enforce, though google "manages" to enforce even more ambiguous requirements on their play store haha. I guess they could make it a guideline or a requirement, and "good faith" devs would comply even if it would be hard to enforce.
It would be waay easier than e.g. deciding if a YT video is for kids.
You can immediately generate all the data by taking all unminified chrome extensions and minifying them, so you can validate your detection accuracy, then flag those that are minified on the store page, and provide some appeal option for devs just in case.
Come to think of it, it could be a chrome extension...