Yep - my understanding from loan docs is that they're life of the loan discounts. Doubt they'll change it if its in your loan contract.
It is one way to get the best deal from individual banks, especially for what ends up being smaller loans (you could end up having sub 4.7% rates with the majors for small loans)...but the time and inconvenience cost of changing lenders probably isnt worth coming up with a strategy to manipulate this quirk.
Cheers,
Red