Yesterday I tried to layout a bunch of program windows via xdotools moveto and resize. In theory they should have been all the same size, but they came out all different, and none had the targeted size. They all had space around them. What is involved in this process? Are there invisible borders, or stuff like that?
Maybe you are running Wayland and not X11?
Nope, I switched back to X11 after I found, that xdotool couldn’t work with Wayland, and ydotool doesn’t support window handling.