With even field dominance the edit or switch occurs at the start of the even field (some equipment, such as vision mixers or switchers allow the field dominance to be set to 'none' which means the switch will occur on the next field boundary after the switch has been pressed).
When there is even field management, the edit or switch happens at the start of the even field (some equipment, such as vision mixers or switchers can set field dominance to 'none,' meaning the switch occurs on the subsequent field boundary after pressing a button).