Cloning Sites, then Domain Mapping

At my company, we publish five newsletters across various healthcare issues. I have built the first at the following domain:

My goal is to clone the site for the four remaining newsletters using MultiSite. Those sites are as follows:

I have MultiSite active and have tried my best to utilize the WPMU Cloning and Mapping plugins but things aren't working out.

Step 1 would be this:

Clone (I assume the clone has to start as a domain...?) If that is the case, I would clone it as the following subdomain: This should clone the entire site, correct? Do I need to have a subdomain already set up on my hosting site, Bluehost? (I tried that already, and it still didn't work)

Step 2:

I need to map that domain to my dev domain: Under Mapped Domains, I don't see any option to "Add New" or where to start the mapping process. Eventually this dev domain will be changed to the main

It is simple in my mind. Clone newsletter to new domains. Change posts and branding. Boom, done.