1. In general, the chair determines whether the working group has
reached consensus. So if changes have been made since the
working group last reached consensus, the chair decides
whether/when there is still consensus within the working group
on the revised document.
2. The responsible AD determines whether an additional Last Call
is needed, if changes have been made since the previous Last Call.
3. When IESG is balloting a document action, and the result is to
require changes to a document, the IESG also decides whether
the changes needed by a document are significant enough to warrant
another IESG ballot once revisions are made, or whether the document
can be accepted immediately once a designated member of the IESG
declares that revisions are made.