Actually, I haven't gotten around to trying Wayland yet! Mostly because i3 on X11 works well enough for me already.

I mean, I literally just plugged in my monitor, then went into Arandr and dragged the funny rectangles a little.

Edit: For reference, my multi-monitor setup is literally just 2 monitors side by side. In my case, I did have to change some settings, specifically set the left one as primary rather than the right one, and make them tile in a slightly different way. But I wouldn't say it involved any "jank" — just some configuration, same as it would on any other OS. (Specifically, I dual-boot windows 10 for some rather silly reasons, and I found the multi-monitor configuration process very comparable in terms of jank or complexity.)