When there are some special circumstances related to the mod's flags section (dashboard), it would be really useful if moderators could make brief notes concerning a certain flag right on the dashboard. Let me explain.
For example, there is a flag on an answer which is weakly substantiated. I handle the issue and leave a required comment. In order to remember to check if the answer was edited and hence upgraded, I do not mark the flag as useful and leave it over for some time. But my colleague can easily look through the flag, see that I left a comment and 'close the ticket'. (Then how am I supposed to find the post then? Per aspera ad astra?) This could be avoided if there was a place near the flag where moderators could leave brief notes, e.g. 'Need to check if the proofs are added; don't put it away.'
This is just one of the possible appliances.
One can say: you can have a special chat on moderation, don't clutter up the interface! But the thing is that, for example, we on Русский язык do not have a chat and my colleague does not want to use it. Moreover, if there are a lot of cases like the aforementioned, how to remember them all? Brief notes on the dashboard are stuck to a certain report and quite informative and rather moderator-friendly.