Is there a way for lowering grid density to about 1cm (independently of zoom)? I only see option for on/off grid.
I can change draw point only at creation or at loading of diagram; then in panel format you'll see "Diagram" and you can change the point of grid.
You can change point density of grid by format panel https://support.draw.io/display/DFJS/Format+Panel you can see it only if nothing of your diagram is selected. Note that the screen grid doesn't change, but when you move or resize object you'll realize it.