It would be great to have the ability for more than one person to be able to use and own a template. Many people on my team use the project templates I make but they are unable to edit the project once it is created since I am the owner. I would also love for them to be able to edit the templates but also keep the ability to edit them myself.
So you can specify 1) who can use the template, and 2) who can edit the teamplate.
In page 1 of the template editor you can click the Project members to default what the Share dialog of projects created from the template will look like–team and individual members and their levels of access to the resulting project (not the template):