Could it not be useful to have a "List of Comments" (LOC) for each RFC? Where experience about the RFC reading, testing and implementation could be listed by the authors (or a successor) from experience and questions received.
These are usually found in the form of working group archives and subsequent RFCs that update or obsolete the older ones, especially in the case of standards track documents. The RFC Editor also keeps a log of notes on RFCs when asked to.
It's not obvious, at least to me, why a second mechanism is required if th one that is there works...