Can we use the same method in this article to duplicate a portal theme within the same NetScaler? https://support.citrix.com/article/CTX209526/how-to-copy-a-portal-theme-from-one-netscaler-node-to-another

Worked for me with a RfWebUI based one. I only copied the files which are really in the theme folder and excluded the linked ones like "strings.*.js". The name of the theme itself can be found in "custom_theme.json" so I replaced the name here also after the copy.