The learning mastery gradebook is great to support competency-driven education. It is a pity, though, that it is limited to the course level.
Several courses within a program work towards the same learning outcomes. Therefore, a global overview of a student's progression for each (account-level) outcome, encompassing all aligned assignments in several courses would be a very valuable instrument for following up their growth and defining the next steps in their learning processes.
This idea is similar to Shawn Sumner's (archived) idea Outcomes Overview for Departments : Sub-account Learning Mastery Gradebook, except that I would not only make this overview available to the department, but also to the students themselves!
Making it possible for students to import this overview into their portfolios would be ultimately awesome! But that might be a follow-up feature idea :-)