Hi again,

I'm an idiot. Let me elaborate on that, so others might learn from it:

I thought that the previews you create for yourself, e.g. by adding portal controls or applications or portal content objects only affect what you see and preview and not what you're able to change/adjust, but exactly that's the point of my misunderstanding. I was used to the static Theme-Designer and expected the same design time behaviour from the UI Theme Designer, which is wrong. The UTD is WYSIWYG (as stated in the SAP help >_<) so controls/parts/elements that aren't reused in the previewed object cannot be polled from the Editor and are seemingly "nonexistent". I assume that's intended / is just how it is - for me it was misleading.

I was always previewing a portal page (still within an AFP shell) for a specific application, so the masthead and the outer layout of the framework page were never invoked and thus never displayed in the editor. Once I switched to the AFP object itself, I got all the properties I needed and expected (just like in ye good ol' theme editor).

So, yeah, it all works, if you use the tools correctly >_<

Cheers, Lukas

EDIT: Still, it's confusing that I can't see certain properties in the UTD, but can then find them lateron in the underlying CSS Files of the generated custom theme. That's kind of inconsistent IMHO.