Extending Astra customizer settings and components

Hi,

I was wondering if it is possible to extend the customizer settings, e.g. add new custom settings under the existing Astra customizer?

Also, would like to extend the Astra header and footer components, e.g. adding additional fields to the button component, or create a new component itself to show up in the header/footer builder.

Has anyone had any success with these kind of customizations? Are there any developer docs/filters/functions that may be used here?

Thanks.