Copy Theme, Menus, Widget settings between EXISTING subsites

Could you create a “framework” site that contains everything you want, minus content? Then, you could import existing content that’s specific to that site. This is what I do to quickly install my starting themes/plugins when I’m building a new site.

Outside of that, I think you’re most likely going to have to come up with a custom solution. I’m not aware of any tools that will copy everything minus the content (and restore only that part to a site).

It’s best to create one subsite with all plugins and themes you want but no content and use that as a master to clone from using a plugin to do make the clones. This “master” site would not be published. You would have to un-publish it after creating it because new sites are automatically published.
This means you may have to make one clone, delete all content and use it as the master.
You could also have just some sample content like a fresh install of wp has just so people have examples.

Thanks for the follow-ups.

WPMUDev Cloner looks like it will do the trick, have to go into Network Admin > Settings to pick what parts to clone, but pretty easy. not exactly generating a mirror of the original site but definitely a time saver with selecting theme, and settings for widgets and menus without overwriting posts.