Have you encountered many/any box-and-whisker plots in the course of your work? On other dashboards?
I´ve been working in public health for almost 7 years and I have rarely seen a box-and-whisker plot. I´ve seen them in journals buy not really for work purposes. I think their understanding is not very straight forward and maybe that´s why not commonly used.
What about histograms?
Yes, I do see a lot of histograms.
If you have little or no prior experience with them, do you think they are easy to understand? If not, can you think of some alternate ways to display distribution data?
I think they are easy to understand if you have some basic knowledge on their interpretation; otherwise, they are not easily understood. Where I work, most of the information generated is intended to be used by the public or other stakeholders who are not necessarily trained in public health and therefore, we don´t use them often.