How can I customize a variable in a review request email template

I am currently using the Vitals App with the Expanse theme. They have automatic review request emails sent out, but there is little customization for the email template. The variable : {{ products|cta:Review product }} is used to display the ordered product(s) to review as shown in the attached photo. We would like to change the format in which the product images and text/links appear including making the images smaller and adding a button rather than the linked text.

There is the option to add an html block in the email template, but nothing else that would help customize the review product portion. Is there a way for us to customize this? We reached out to the app developers and they said that there is nothing they can currently do to offer customization.