I’m in the “inner monologue” camp. Most of what I think materialises as thought words. I don’t have to move anything in my throat to do that unlike OP though, I can think in words without mumbling to myself.
But I know the voice can’t be all. It’s difficult for me to think in words while actively saying something, but I can have new thoughts while speaking. Sometimes, I get interrupted in thinking mid-sentence, but then I return to that sentence to finish it because… it’s just satisfying? It’s not that I learn anything new.
I feel like I don’t have very much imagination any more. Its hard to produce images in my mind, not impossible but I do have to concentrate - remembering images is easier.
Weirdly, way harder to me: imagining a voice. Inner voice is what I sound like to myself, I can remember and replay songs and quotes as I heard them, but having any voice say anything is hard, especially female voices. Went through some examples in my head couldn’t make anyone say anything - until I thought to make different tf2 mercs sing “Oh Canada”, that somehow worked despite me definitely not having heard that before. Brains are weird.
I believe you are acting way too definitive about something rather unknowable.
For example, what is Aphantasia then?