Hi there. That is actually not true—you can completely hide the crown icon for free directly from its own popup. If you click on it, you will see a link at the very bottom that says "Hide Showcase Icon Permanently". No payment or premium subscription is required to remove it.

To clarify, this extension does not monetize AO3 or any author's work. It is a client-side tool built strictly to help readers organize their personal reading dashboard. The premium tier simply helps support the independent development and maintenance of the software itself. I highly respect the fanfic community, and the option to remove the icon is right there for any user who doesn't want to see it!