Just to go back to first principles on this. Discourse is not creating pop-up windows. There’s some issue with the code in Firefox – specific to that browser, no other browser that we know of does this – that when you middle click body links, Firefox thinks that’s a pop-up window.
This is incorrect. It isn’t.
So, if you click the “Options” button there and then select “Allow pop-ups for bbs.boingboing.net” – even though these are not pop-ups, and BBS does not use pop-ups, you’ll be fine.
If it helps, you can think of it as a
Stop thinking bbs.boingboing.net is producing popups when it isn’t
option. Which you can set once and forget.
It is unfortunate, but body links are never pop-ups, despite what Firefox alone among all browsers might think.
(Note that you can set links to open in new tabs by default in your user preferences if you like, as mentioned earlier in the topic.)