Re: So long and thanks for all the Flash!
Nod.
I noticed this through seriously enjoying an online version of xkcd's Hell Tetris (ref https://xkcd.com/724/ - strangely calming once you've got the knack and if you're annoyed at it you can just smash the bricks around instead!...)
The proposed resolution for Chrome users seems to be the SuperNova extension, but on Chromium the flash interstitial depicted here becomes an alternative "we recommend SuperNova" one which at present reappears no matter how many times you (re)configure the plugin, click the widget, insist flash runs just this once, and reload the page etc.
Fortunately I haven't ever needed it for anything serious.