Grasshopper for Rhino style canvas split:
You can extend canvas horizontally or verticaly in place.
Grasshopper description from https://bimcorner.com/8-grasshopper-shortcuts-which-you-should-know/
“Press left Alt and hold it, click on the canvas and drag the mouse to sides. A vertical line with an arrow will appear on the screen, letting you extend your canvas horizontally. You don’t need to worry about existing components because they are going to move along. If you would like to move your components in the vertical direction just press left ALT one more time and you will split canvas with a horizontal line. In that easy way, you will get more space to create your script. “