I keep mine a little lower if I don’t it raises the level in the display to within 1/4” from the top. You will have to play with the water level in the back area to get the display area where you are comfortable.
B - It might not even be possible for scenario A in some AIO tanks - Waterbox peninsula mini 25 for instance the return chambers divider/bubble trap is much higher, meaning the water level has to be higher to work anyway (Red line added in to show what i mean)