Unfortunately, adding multiple dynamic comment boxes for a single option isn"t supported. As a workaround, you can insert a separate comment box question right after the original question. Use the plus (+) icon to add additional text box, then apply dynamic show/hide logic on the text question to display it based on the selected option in the previous question.

You can refer to this help file for guidance on applying the logic: https://www.questionpro.com/help/dynamic-show-hide.html