I don’t use .desktop files that much… But I guess xfce is X and not wayland. Check the DISPLAY env var for your user and set the same in your script there or run the binary with that env var.

I find it very useful, and it conflicts with normal copy paste very rarely. There are two clipboards, one is filled with latest highlighted, and the other with latest Ctrl+C:ed. Middle click pastes from the first, Ctrl+V from the second. This makes you able to copy two things at once: ctrl+c something first, highlight something else second, paste in any order. The confusing thing when learing to use it for me was that since I need to highlight to ctrl+c, I will overwrite what is in the middle click clipboard, and it also means you cannot highlight something to replace it with whats in your middle click clipboard. It does however mean that most times you want to do a ctrl+c/ctrl+v both clipboards are in sync. Not sure why, but I often find myself having to copy/paste two things at once, and I use both buffers without thinking. Which makes it impossible to use macos.

“Other Unix-like”, do they mean like open/free/netBSD and that class? Because macos does not have that, right? Only some terminals emulate that behaviour by overwriting the normal clipboard, making it very hard to switch between them.