The new highlight bar on top of window panel is a good start. It’s not enough to be able to identify quickly which window is where when they are all stack on top of each other.
Here is an example of multiple windows open in a dark station. Sometimes I want to resize a window and it’s hard to find its border.
+1 for that. Especially in dark envrironment windows are really hard to distinguish. I can’t count how many times I closed wrong window. I know about “brightness” setting but I won’t burn the entire image to make those windows stick out a bit more and have my screen only few months old and calibrated so it’s definitely not burnt yet.