All the above have been such a blessing! For another who has a copy of Quidditch Through the Ages or Hogwarts: A History will agree how adorable the little annotations made by hermione harry and ron are. I do also have to mention that I have appreciated the hogwarts legacy game and the LEGO games. However, hands down best of all are the illustrated books by minalima and jim kay. I'm not sure if they count as supplementary material but definitely an addition we never knew we needed.

PS I've also recently acquired wizards chess which I'm obsessed with and definitely have harassed my friends and house guests into admiring as well.