Well, you can create a dynamic footer snippet based on the segmentation, and use that in the email asset you build. Alternatively, you can also create an edible module in the template and make it dynamic based on the segmentation in the email asset, but the dynamic snippet would be a better choice overall. Check out this article on the product documentation. Also, with the snippets, you'd not need to re-approve all the email assets on approving the updates unlike the changes made and approved at the template level. You can approve all the emails in one go while approving the snippet using its no-draft functionality.