Hi,
Since version 9.7.0 you can add and configure an unsubscribe survey with predefined answers on the unsubscribe page. The unsubscribe reasons will be available in the user's history and in the list edit page.
In the configuration you can specify you want to display the unsubscribe page within your own template. In case you want to change the way the unsubscribe form is displayed you can customise it using css. In case you need to make changes in the html you can create a page override. https://docs.acymailing.com/developers/create-a-page-override