In WorkBook workflows, you can use the Backspace key, but the Delete key doesn't do anything. I can't find any empirical evidence related to the frequency of clicking either, but I'd bet that more people use Delete far more than they use Backspace. I know that I am a regular Delete key user, and several of our business testers are as well, and we have found that nothing happens when we press Delete. This is a harsh bummer. Why would the product limit this?