I get that it may sucks, but it is better to get an alert message? Or just do the rendering glitches?

What is cool about this project is stuff like this. >The presentation is displayed in a simple X11 window colored black on white for maximum contrast even if the sun shines directly onto the projected image. The content of each slide is automatically scaled to fit the window so you don't have to worry about alignment. Instead you can really focus on the content.

One can tell the author really had to use this deck in real situations.