Here are EPA-driven assessments that show that there aren't vast differences in EPA by punter, but even when there are they aren't on the field enough plays for it to have a significant cumulative effect throughout a season. A best punter adding 2-3 points per SEASON is not getting you very far. I'll look for other stuff as I can here.
https://harvardsportsanalysis.org/20...f-nfl-punters/
https://www.bigblueview.com/2022/6/1...an-riley-dixon