I had the same requirement and yes, K2 forms were showing the most recent versions.
I created child list to store comments then created a view to store comments in list format. The list view was added on add, edit and view forms.
Did you use the Append columns at all? or did you use an extra separate list where you stored all the comments? you used the parent-id to link between the two lists right?
I created an additional child list to store comments. Yes then key from master list to link it to list that stores comments
Thank you. I will follow the same route.
Please do update if you run across a better way or another solution.