My idea is to create a base administrative panel, where I can use the next sites, without having to copy and paste. In the base I have only the control of users and menus, the rest I am creating packages and require each new site only what is necessary. You're all in the packagist with webhook set up. So when I create a new website, I do:
composer create-project meuusuario/meucms novo_projeto
So far so good, but I can not make other projects dependent on the base.
For example: if I changed something on the base, others will update via composer update. Is this possible?