Trying to clone library into a NEW Roon Account

Both machines I am using are Roon Rock machines. I have an extensive Roon setup with 4 TB of music, and many customizations including some of my own Genres. I am trying to clone my library onto a new Roon Rock that is exactly the same as my other one. Both servers have an internal 8TB SSD for the library. I have setup the 2nd one with a fresh Rock install, and have copied all the music files to the 8TB SSD. Then I restored to the 2nd server the backup from the 1st server. When I log into the new Roon account, and go in for the first time, it re-imports all the music fresh, I am losing all my custom Genres and work on my music.

How can I clone this library to another machine/new account so I preserve my hard work and library?

You can’t. Roon’s database is account based and therefore you have to start fresh with a new/other account.
What you can do is to make sure that as much of your deviations from Roon’s standard metadata as possible are in your file’s metadata and then use appropriate import settings in Roon.

You can clone it to two servers that share one license (alternating) or have two licenses that are owned by the same Roon account (following this procedure), but you cannot clone to a server with a license that is owned by a different account.