I started a conversation here about spec change processes. I think the important thing is to start having conversations in one place because they're a bit scattered at the moment.
@issa, that post links to some conversations about namespacing but I don't think they say anything explicit about appearances. Appearances can be client-specific and are passed through by some form generators like pyxform (though not Build). There was some conversation about it and the conclusion was that they're loose by nature and that exposing namespaces to users would add some complexity without clear benefit.
@Neil_Penman annoying to be blocked on this, I know! Imprecise or ill-considered naming has been a problem in the past and I imagine there will be more decisions like this to be made so it's probably best to take a little time to make sure all the right voices are heard before a decision is made.