Customizing social shares can be done by creating some share buttons, and adding links to them. The additional step would be to generate the actual social share link, which you could do using this tool: https://www.sharelinkgenerator.com/

Then you could just copy that link and add them to the social share icons in the Vuture email.

Vuture does this step automatically when sharing the content of the email and then Vuture adds the page link in dynamically. If you want to share a different page, you would have to use a different tool to generate that share link, but you can then add it to the campaigns wherever you like