Hello, John.
Thanks for reaching out to our Microsoft Community Forum and please accept our sincerest hope that all is well.
We understand that you would like to add additional columns for comments in a Microsoft Loop Component which right now cannot be done.
As explained in the link below, Microsoft Loop is still in Public Preview. As such, there are still features that need to be improved, and so problems like the one you have can't be solved right away.
In any case, the bellow should let you add an additional column:
- Open the Loop Component in your Microsoft 365 Insider account.
- Click on the "Settings" icon in the top right corner of the component.
- Select "Edit Component" from the dropdown menu.
- In the "Edit Component" window, click on the "Add Column" button.
- Enter "Comments" as the column name and select "Text" as the column type.
- Click "Save" to add the new column to the Loop Component.
In the event that these steps do not work for you, you may want to contact your employer's I.T. department for help since as explained in the link above, they do have full control of what features are allowed or not in Microsoft Loop.
If they are an unable to help with this issue, please also provide your experience as feedback to our developers. They'd love to hear from you about what's working well, what's not, and any ideas for improvements, including possible new features and functions. Your contribution will help us improve the user experience for you and all users around the world.
To send us your feedback, go to the bottom right corner, select Help, > Send feedback.

On Android or iOS, tap your profile picture in the upper-left corner to find Help and feedback.
Thanks again for choosing Microsoft! We are here when you need us.
Sincerely,
Glenn Rue
Forum Moderator
Microsoft Community