I was trying to figure this out until like 3AM last night. How do I set environment variables to be loaded into my X session when XFCE loads? I'm on Arch btw. I want to set DRI_PRIME=1 so that applications started from the launcher actually use the discrete graphics card by default. Right now it only works like that if I launch from the terminal.
I tried multiple potential config files to put it at, and the one time it actually worked, I lost my window manager... The other times, the desktop environment didnt even load or start the session. Undid everything and decided to come back later.