It would be nice to also apply overrides to <iframe>s such that the user gets consistent overrides whether the target web page is the topmost frame or an <iframe>. Here’re some use cases:

Google Maps embedded into other web pages

The Keepa browser extension inserts an <iframe> into each Amazon product detail page.

It would be better to display a favicon or a user-defined icon for each override in both the list view and the detailed view of overrides so that the user can more intuitively identify what website(s) the override is for.

https://angular.io/

It would be better for the user to be able to sort the list of overrides by different fields, such as Title, Time of Creation, Time of Last Update, and Active / Inactive Status, etc.

This browser extension should use the WebExtensions API (along with some browser-specific code) instead of the Chrome Extensions API to achieve maximum cross-browser compatibility.