you can't make donation for the browser development (mozilla corporation), only on internet activism (mozilla foundation)

not sure which part is "a little more difficult" but it's just go to their website, login, go to library, select the game, and finally click download offline installer.

I'm fine with it as long they provide toggle to disable the behavior. It would be even better than current javascript implementation as this way I can disable it everywhere.

The toggle exists in chrome though it's in flags page instead of settings.

Except they won't want it if they're going to actually read the page. With lazy loading, every scroll may mean waiting a few seconds before the content loads and they can't just let the tab open and wait until the page fully loads.