The Level window of the 4 window view can be set manually to a width and center point. Unfortunately these can only be set to integer values. A window between e.g. 0 and 0.5 has to be scaled using the bar directly. If this can be done via "Change Scale Range" , it would be very cool.
The latest release(s) provides Color-LUT, which is very helpful in e.g. PET. It would be great if the Level window could show a Legend for the LUT.