So the answer is not to allow separate pop-up windows (I don't), and always use a flexible ad-blocker which can also include mining code in its block-list databases. I use 1Blocker for iOS Safari which seems to do a good job and is even extensible in that you can add user-defined block rules for additional annoying elements. The latter feature is driven by an excellent ‘annoying element selector’ visual user interface which takes away the time-wasting nightmare of having to write block rules by hand in some language or other (maybe CSS or something akin to it plus addition stuff) and get them right.