I have fallen into the habit of excluding most proper names from my vocabulary. As I read, the (previously unseen) names of people and places are in blue. I put the cursor on those, and then hit ‘x’. If I kept them, my vocabulary count would probably be 15% higher. Just as a matter of interest, you might provide a statistic that separates minuscule words from cap words, in the total of ‘known words’.
In some cases, having a proper name included makes sense. A case may be evident in the spelling, or, the spelling may be quite different (Brésil vs. Brazil).
I almost wish I could stop zapping the caps. But now that I’ve started… lol!