I can use templates defined in one central "catalogue" project to mine without loosing customization done on perm side

When I select a project/tracker I want to copy, there is a check that I have all the elements (user groups) in my project to perform the copy;

When the groups needed by the template doesn't exist in my project, I have a message to inform my. I can abort the creation or force it.

When the groups needed by the template exists, I have a message that tell me that the groups exists and I can continue but members are not checked.