So you ask professors for letters and then some of them don't even get used?! I think that's ridiculous. Why waste a faculty member's valuable time if you're not actually going to use the letter??? I'd be furious if I found out I spent time writing a letter that didn't even get utilized!
I'm not criticizing you, as I understand that this is your school's policy, but I think it's really unfair to faculty members to encourage this practice. Plus, this sort of screening of LORs defeats the purpose of the "I waive my right to see the letter" thing, which presumably allows faculty members to be fair in their evaluations of an applicant. By your school's committee acting on your behalf to screen LORs, they in a sense prevent admissions committees from getting a good picture of what your professors have actually said about you, since they presumably weed out "bad" letters and only include the best. There's a certain degree of pre-screening that already goes on anyway, as you only ask for letters from people who you think would write you a good one. So why introduce another complicating wrinkle into the equation? One might also argue that it allows students from your school an unfair advantage, in that you can still "waive your right," but the committee basically acts on your behalf to select only the best letters. I don't think such a practice should be allowed by the AAMC or medical school adcoms.
Does anyone else know of practices like this going on at other schools???