Very nice writeup. I ran into a few sites last year that used this and attempted to reverse engineer it myself. I failed miserably because I know nothing about code in the browser, but for some reason it really piqued my interest.

The question that kept coming up for me is, will the arms race ever end? Are we doomed to the fate that consoles had where the entire device is locked down?

I am reasonably certain that it won't be long until ad-blocking becomes a whole different ballgame. Ublock will become an ever-updated trained model which real-time blocks ads. I have always wanted ad-blocking smart-glasses. The browser soon won't be any different. See Minority Report for an idea of where ads are headed (and then think about how to counter-act that, voila, that's how things will be)

Only if there's enough demand for the content to overcome severe inconvenience.

Which means Netflix with its exclusive titles does require approved devices. But a random internet website is not likely to be in position to demand too much.

This is interesting, especially begs the question whether Apple or Google browsers that no longer allow anything more than filter lists would be able to defeat sophisticated anti AdBlock attempts.