Copying/cloning sites from 1 WPmultisite to a different WP Multisite

I’m looking for the ideas on the best/smoothest/quickest way to copy a site between WP multi-site installations. Specifically I’ve got two use cases that encounter frequently enough that I need a better workflow than just create from scratch.
Case 1: A WP multi-site install exists at domain.x. There’s a particular subsite there with specific plugins and themes activated. It’s at domain.x/site-y I need to make a duplicate of the site at a different WP multi-site install at domainB.x and call the site domainB.x/site-z What’s the best way to do this? Ideally I’d like to clone the whole thing: theme selected, customization, plugins, forms, and a few posts/pages.

Case 2: I need to clone/copy and entire WP multisite, including all the plugins, themes, and all the sub-sites. For example, I’ve got a WP multisite installed at domainC.x in the root. I want to duplicate it at domainD.x. Installatron doesn’t really do this since it really only does it for creating a new single install as far as my experience goes.

For both cases, I’ve got cPanel and WP super admin access to everything. The differnt domains are in different cPanels