I guess I'm less fearful of that than opening an entirely
new and decidedly less investigated area as part of the
wg's deliverables.
On the contrary, I think that you will find that the supervising AD
alone has put rather more man years into this particular issue than the
entire ESTG group.
The workings of PKIX are understood in exhaustive detail. The workings
of XKMS have been debated for 5 years by a group that is rather larger
than the one that reviewed DKIM.
Nobody is proposing developing a reputation mechanism - at least not
yet. Dave Crocker made exactly the same impassioned plea to restrict
scope in MARID. Then once he had excluded the existing mechanisms using
the charter he made his own proposal.
Fool me once...