Not super critical, but quite annoying.
To elaborate, on my 4096x4096 in heightmap (black/white) 2d mode, on zoom out the full map is shown.
but when zooming in it cuts off a fixed amount of pixels on the sides of the map, unable to view the details up close.
Id say its some 25/100 pixels wide which is no longer visible (rough guess)
Neither manual mouse move nor vertical/horizontal bars allow me to show all the details.