I really like the concept of bringing i3-style tiling management to the browser space, but why is it specific to messengers? Since most well-designed websites work at any size, couldn't you just have a permanent tab at the side of the screen of, say, twitter, or some browser-based IRC client? Admittedly, I'd probably use facebook messenger as this tab anyway, so my needs are covered, but it seems like a missed opport…
Opera had tiling some 12-15 years ago. By default tabs were just 'maximized' to the full window, and they made it harder and harder to access with subsequent versions. I'm not even sure if it made it to the latest presto release (version 12). Edit: the Wikipedia page shows tiling in Opera 1.0 in 1995... https://en.wikipedia.org/wiki/History_of_the_Opera_web_brows... I'm with you though. I dumped Opera the moment they…
Sure enough the tiling feature is there. Right click the tab bar and go to the arrange menu.