Some colleges that write committee letters without defined restrictions nonetheless report excellent medical school acceptance rates (note that students with sub-3.5 GPAs were not deterred from applying):
*Q: What is Hamilton’s acceptance rate to medical school?
A: Hamilton’s acceptance rate to medical school over the past five years has varied from a low of 76% to a high of 93%. More than 92% of students with a GPA of 3.5 were admitted the first time they applied. The Hamilton College Health Professions Advisory Committee prepares a letter of recommendation for any student who wishes to apply. There is no GPA requirement to receive a letter of support.*
https://www.hamilton.edu/academics/healthprofessions/premedquestions.html