They are not inherited for a reason. The most common use-case for exporting main components in UI design is probably when you want to export icons for development. If every icon also inherited export settings in instances, exporting all the assets from a file at once would result in a ton of duplicate icons in the exported package.
That makes sense.
It would be great to be able to turn this option on or off. For our company’s purpose, it’s incredibly useful for them to be inherited for this particular context.