@ChrisWard2026 I'm pretty sure Opera does ask that when you first install/run it, though it opens as an inserted line above the main browser window rather than as a pop-up window.

I visit certain websites and they drive advertising revenue by opening new tabs to other sites, despite having pop-up blocking enabled, would it be possible to add an option to block certain websites from being opened, either completely stopping tabs/windows to them being opened or by simply not displaying their content and a "content blocked" message?

Would work best as a right-click menu option in the URL window, once a undesired website has been opened, with a choice to block that specific page or the entire domain.