Thanks for the suggestion. I have been looking around quite a bit for a solution for using rubrics in combination with "unlimited grades".
I feel it would be particularly valuable if rubrics had an option to force the rubric to simply sum the point values assigned each level, instead of calculating percentages out of points possible.
An assignment graded on a Proficiency basis is an important example of where this would be essential, i.e. Proficiency is... (not demonstrated • developing • proficient • exceeds expectations). While it may be impossible to exceed expectations on more than a few criteria, in this system, the "exceeds" level should be at or just below 120% and should compensate accordingly in the total grade for a criteria marked "developing". This is a useful system with the rigor imposed by requiring any student scoring above a B+ (89.99%) to actually exceed expectations on a regular basis.
Rubric calculation based on simply summing points with "unlimited grades" would be very valuable to implement in Moodle.