There have been 3 issues I've had regarding it, 2 I'd call minor:
- I haven't found a way to rearrange external displays, though it is theoretically supported
- After a bug in my TV switching to the lowest possible resolution through switching the input in home assistant it would not work with 4K again until after a complete reboot (so it may not even be a wlroots issue)
- XWayland apps are unresponsive in the upper half of the second screen (4K at 1x scaling)
Using mostly native Wayland apps neither of these have been deal breakers for me. Something under-discussed is that virtual desktops are per-screen, which I find quite cool.
So that's my adventure with Wayfire, but I would assume that Gnome and KDE have perfected multi-screen usage on and off of Wayland by now.
[0]: https://wayfire.org/