Display calibration helps to detect any possible issue with your display.
The boundary could be used to check if the whole display area currently being utilized. If there is missing area, it may caused by over-scan or wrong HDMI setting.
Wrong HDMI settings could cause missing lines and also your display could have dead pixel. There are two buttons one for horizontal lines and another one for vertical lines. Each time you press one of them pixels move 1px, at-least ten clicks needed to check all pixels in each direction.
On DLP 3D printers there is need to check focus/tilt of the projector. Red grid does not cure the majority of resins.
To inspect display this option could be used, also to cleanup resin by curing single full layer to collect all dropped cured pieces could be used.