The presentation software itself (Excalidraw) makes this nearly unusable for me:

When it opened up the entire left-half of my screen is blank, and the diagrams are obviously cut off on the right. There is no apparent way to scroll horizontally (excepting a mouse with a horizontal scroll mechanism of some sort): There is no horizontal scroll bar and neither the arrow-keys nor click-and-drag serve to scroll horizontally. Zooming out made things a bit clear what was going on, (margin notes shifted the content far to the right).

Firefox, 1920x1200 screen.