As said, it depends on the definition of platform for this case. All I see is support of a bunch of flavors of one platform, namely POSIX, unixoids, or how you want to call it. Yes, they are different desktop-platforms, but the purpose of this software is still limited to one specific environment. Or to give a different perspective, nobody would call it cross-platform, just because it can run with Gnome and KDE, under X11 and Wayland.

And I'm curious how much adaption happens for each OS really. Are there specific changes for MacOS and BSD, outside of some paths for configurations?