Slides with scrollbars are not keyboard accessible

[AmeliaBR]

The slideshow JS maps all arrow keys and PageUp / PageDown keys to the next/previous slide behavior. This means that if a slide is created that is too long to display in the viewport, there is no keyboard-only way to scroll it.

As much as a well-designed slide wouldn't have scroll bars, not everyone is design focused (came across this problem trying to read a slideshow in which each slide was a full page of text). And even if the slides are sized correctly for display on a projector, they might be distributed to people who just want to read the text on their smaller-screen device.