Regarding the differentiated branding, I've been hoping for a GrapheneLite for many years now.
Regarding direct AOSP support, there are many devices that work fine with just the generic system image, which I'd count as direct AOSP support.
Regarding direct AOSP support, there are many devices that work fine with just the generic system image, which I'd count as direct AOSP support.
I believe nothing prevents other individuals and organisations from building what you're suggesting with GrapheneOS code and ideas.