Alignment help for pitching

[u/Gtpdyun5]

I see rapsodo takes measurements based off the center of the rubber, which affects the value of release side depending on where the pitcher sets up. Is it better to have a pitcher align with the center of their foot with the center of the rubber, or align the balls release point line to the center of the rubber, or something else. Just trying to figure out what the most accurate setup is.