The only use I've ever had for XEyes is, ironically, under Wayland. I use it to see quickly which apps are running natively as Wayland apps, and which are using XWayland. The eyes don't follow the mouse when you hover over a native Wayland app, but they do for XWayland apps.
There is a configuration option for Sway that will put information into the title bar to tell you if the window is XWayland or pure Wayland. But I forgot the exact option. It was mentioned in the Sway documentation.
It's actually been a while since I've used Wayland, but that's good to know.
My current mix of OSes is OpenBSD (cwm on X11) for coding, iPadOS for casual consumption and note-taking, FreeBSD on a home server, macOS for work, and Windows/Nintendo Switch for gaming.
