You can manage commenting and the comment summary panel on a page-by-page basis. 

Users can collaborate on boards by commenting on cards. As a page builder, you can manage commenting at the page level. 

To enable/disable commenting at a page level:

  1. In designer mode, select the in the upper right, the Page settings from the dropdown.
  2. In the Commenting tab, switch the Enable commenting toggle on or off. 
  3. Select Apply.
    Once disabled, users will no longer be able to comment on cards.

To enable/disable the comment summary panel:

  1. In designer mode, select the in the upper right, the Page settings from the dropdown.
  2. In the Commenting tab, switch the Enable comment summary toggle on or off. 
  3. Select Apply.
    Once disabled, users will no longer be able to see and select the Comments  in the top-right of a page to view a summary of all card comments. 

Note: To enable users to comment, but prevent them from seeing comments tied to context settings they're blocked from through selective access, you can switch on the Enable commenting toggle, and switch off the Enable comment summary toggle.