Update: A partial fix is now available.
Patch the display panel driver:
Then use a xrandr command to crop it back to 1280x480:
xrandr --output DSI-1 --mode 485x1280 --fb 1280x480 --transform 1,0,0,0,1,-5,0,0,1
This hack clearly shows that the display scans from bottom-to-top in our view, or left-to-right in the panel’s native orientation, in contrast to what is specified in the known commands in the driver…
That’s why the newly extended height accommodated the top lines instead of introducing out-of-panel pixels 
