Thanks for your comments which were very helpful (and I'm very pleased someone has read my essay!) I love John Wheeler and, as you probably noticed, referenced him in my essay. You are quite right, the idea of change doesn't immediately provide an ontology of the world, i.e., what it is that exists in the world. If you are an 'idealist' you can say the world is made up of 'ideas', or rather all the things you experience, such as 'green' or 'blue', and that would be a type of ontological explanation (would you agree?). But colours also have a frequency, so, in a way, they are also change, and then saying the word change is simply the same as saying colour (and vice-versa) and, therefore, is a type of ontological explanation - or is that just semantics? So, I guess, in that way, the idea of change does provide an ontology of the inner 'conscious' world simply because it is another word for all the things, such as colour, that make up that world. But you make an interesting point in that if the change in consciousness is modelling the real world (the world outside our brains) then it must be modelling change in something, but change in what? As in the story of the alien's room in my essay, it would seem impossible to give an answer to that question - so, bizarrely, nobody can know what is changing on the outside world, and then the outside world has no ontological explanation. But the key thing is, does that practically matter? Probably not!
I thought you might find this interesting (or challenging!) as it calls into question the very idea that an ontological basis for the world outside consciousness is required or even possible.
Thank you again for your comments and all the best,