Change default mockup project options
You can set default options for new mockup projects using the ph_project_meta_box_options filter. This will let you set specific defaults for projects when you create new mockup projects. This will not affect your existing projects, only defaults for newly created mockup projects.
Here's how you'd set those defaults with a filter. You'll likely add this to your theme or child theme's functions.php file and modify the 'on' or 'off', and 'public' values as necessary: