I don't know. Looking at the live map, waze gives me two alternate routes
from Ann Arbor, MI to Hamilton, ON one through straight at 241 miles and 3 hrs and 36 minutes. The other 442 miles and 6 hrs and 49 min going south of Lake Erie. So the delay at the border appears to be much less than the added time to stay in the US. Routing to anything farther east including Niagra Falls, ON, waze only routes the longer route. There seem to be freeways connecting the entire route through Canada. Waze has no problem routing from Hamilton into New York. So I don't why waze insists on staying in the US at the cost of adding a couple of hours of travel time.