Load WP_Customize_Manager outside of Customizer

[BaronVonPerko]

I'm not sure if this is possible, but I need to be able to load the WP_Customize_Manager object outside of the customizer page itself.

Essentially, I want to be able to get all the existing panels, sections, and controls that already exist from the WordPress core and the currently active Theme.

I'm wanting to be able to get this information out of the REST endpoint here: https://github.com/BaronVonPerko/wpcui/blob/v2.0/inc/API/CustomizerLookupController.php