I'm not a core developer, but writing the patch is usually considered helpful. Two notes:

1. Make sure to write unit tests for any new behavior
2. I'd suggest making any such argument keyword-only; if we move closer to the Java executor model, that means having a lot of options, the majority of which would be left as the default by users. Binding the API to a particular argument order is sub-optimal (it makes it even harder to deprecate arguments for instance), so enforcing keyword only behavior ensures users can't write call lines that take dependencies on argument ordering.