The Getty Center website published an article that points out examples of diversity in medieval miniatures: https://www.getty.edu/news/the-black-knight-of-the-round-table/
The article was published on September 1, 2022 by Meg Butler, in conjunction with the Getty's new publication The Fantasy of the Middle Ages: An Epic Journey through Imaginary Medieval Worlds
There are examples of from manuscripts I'm not familiar with, so I thought others in the forum might find the article of interest.
Thank you @Mary Yaeger for sharing, this is so timely and important.