How about this super late response?
Just created an unofficial doc for a customer about Complexity Scores (aka Complexity Indexes). Complexity Score in Governance Dashboard.docx
In general the guidance is to experiment and observe - adjust the settings based on your experience. For example, if you have 512 GB servers and apps have 100- 200 million rows of data on average, you might consider changing the "Rows" index to min 50 to max 260 (default).