This probably more a feature request.
Maybe some of it is already possible.
Questions about added comments to a gridcell:
1. Can a Comment be added without display the little triangle ?
2. Is it possible to show/popup the comment by clicking on the cell itself
3. Is it possible to change the comment popup-properties:
a. Popup Arrow up or down ?
b. Thickness of the border
c. Font of the text within the Comment Popup
Perhaps (some of) these issues can be implemented by (new) properties,