Ah, good to know. I'm not sure if they changed that since launch, or I was just conflating them with one of the other extensions.

This sounds more like Safari's newer behaviour, which sounds good in theory but in Safari's case where it can't be turned off, it breaks things in practice. This seems like a good solution for people that are aware of what's happening enough to pay attention and disable it when something is not working as expected, but makes a bad default for the typical user.