FD, bp;- with some devilment, flown many monitored approaches but not in this context.
To confirm correctly identified visual ref, then the PM has to be head up; if so the mental process will require 2-4sec to get into the loop - to understand. During this time who is monitoring, and what is or needs to be monitored; and what happens next.
What if PM disagrees with the vis ref assessment. Doesn't matter, so why check.