The 2020 census undercount in rural counties finally clicked for me

I was digging through the Census Bureau's post-enumeration survey results last week and found that rural counties in Mississippi had an undercount rate of about 5.8% in 2020, nearly double the national average of 3.3%. That surprised me because I always assumed the undercount was mostly about urban areas with renters and language barriers. Turns out, the biggest gap was in places where people distrusted the mail-in forms and where internet access was spotty. I cross-checked that with a 2022 report from the Mississippi Center for Investigative Reporting and it matched. Has anyone else looked at how local outreach budgets affected those numbers in their state?