This would be a great functionality! There is currently commenting in the Response Ticker widget type. I've just posted a new product idea for commenting in other widget types (such as the Record Grid widget) and have also referenced your question there.
Feel free to upvote the product idea here

Response rate is very basic metric which doesn't work effectively on Qualtrics. I would request the Development team to create Response Rate Widget where 1) it should be able to show the overall Response Rate (total responses received / Total Email sent), 2) it should be able to show the Response Rate of different Surveys under the main project (total response received for Survey ABC / Total Email Sent for Survey ABC), 3) it should be able to show Response Rate for all Surveys separately under the same Project on the same chart with percentage or nos (Total responses received for Survey A, Survey B, Survey C, with dividing each project with Email sent for each Survey with duration weekly/Monthly as X-axis), 4) Respondent Funnel should also have an option of bifurcating email sent and other details based on Surveys under main Project. 5) Many graphs/charts don't work with Response Rate should also be sorted. This is very important and urgent need so I would really appreciate if the Development works on it asap.