Honestly it would be better to bake in source control context so you can mark new code as more strict than legacy.
You can usually achieve this by adding ignore pragmas to your legacy warnings (although you need to touch that code). But at least that way, daily workflow will see errors and you can find the legacy errors by disabling the pragma.
You can usually achieve this by adding ignore pragmas to your legacy warnings (although you need to touch that code). But at least that way, daily workflow will see errors and you can find the legacy errors by disabling the pragma.