So since I understand the concept of “per capita”, I’ll frame it that way. Is there a way to count how many views a post has vs how many recs, and make a “Per Capita Best” list?

Done. In the 'Best Of' lists, the previous "Recs" column is replaced with a "Recs (%)" column which is the ratio of the recs to the unique views. One users viewing many times still constitutes as a single view. I finally multiply the ratio by 100 because expressed as a percentage to be a little more friendly.

This is a little less elegant than showing Recs directly in the Best Of lists, and part of what makes Shrewd'm great is that it puts simplicity and clarity first. However the rec/view ratio is so objectively more meaningful as a means of ranking that the lack of elegance is outweighed by the greater truth.

I do make use of “Vanguard” boards thanks to your link

I'm really glad you use this! And thank you for posting to lower volume boards (ie. boards on the vanguard) occasionally. They'll be only little more visible with the adjusted Best Of, but the trick to life is gradual improvement, which compounds over time.

- Manlobbi