Custom branding possibilities

Does the PFD Embed API offer any options to change the branding, replace or remove the logo?

I found, and tried options below, but cannot see any effect:
- showBranding: false,
- showTopBar: false,
- useDocCloudLogo: false

Where I can find all available previewConfig options documented ?
Do you plan to add possibility of custom branding for PDF Viewer, assuminng it's not yet available ?

Thanks, Przemek