Hello,
Is there is a formal process, how to request/discuss enhancements to the DUE CORE libraries?
Yes. Start by creating an issue here...
If you have a proposed fix (which you do), fork the Arduino repository...
Make the changes.
Create a poll request referencing the issue you created.
A good place for discussing changes to the Arduino software is the Developers List...
https://groups.google.com/a/arduino.cc/forum/?fromgroups#!forum/developers
Most / all of the information above is available from the Arduino Home Page...
http://www.arduino.cc/:
Development
For information on the development of Arduino, see the Arduino project on GitHub. Changes to the software are discussed on the developers mailing list.