FYI Canada is a weird one. For one of their spots you might want to go "get last winner" for the Canadian Championship (FA cup which includes the 3 MLS teams).
US and Mexico might throw up weird qualifiers too, they were always hardcoded in a weird way for continental comps. "Get last winner"s for MLS Cup, Open Cup, and the two conferences (with get last runner-up as backup checked) might be better for the US, and something similar for Mexico's opening/closing.
Brilliant work though, looks great.