Generally works fine but flashing, when switching from a tab selected by default, sometimes can be really annoying. And if the default selection is taken from a youtube's tab, it still starts playing the video.
I understand that most likely FF doesn't provide any better way to do this in the moment but that's an issue nevertheless.
Yes, there is no better way. There is a related active Firefix request: https://bugzilla.mozilla.org/show_bug.cgi?id=1419947 . I hope the solution 2, which allows extensions to override the default switching, can be accepted.
