OK, the issue between us is your spatially finite universe vs. my spatially infinite universe; maybe also stated as a finite field of aether medium, vs. an infinite wave carrying aether medium.
Let's test our mutual understanding of "finite" and "infinite", specifically in regard to the extent of the three spatial dimensions. Logically, finite space is measurable because there is an end to space in every direction from any point within a finite universe, though we cannot measure it. Infinite space, logically, is immeasurable because it has no end-point in any direction from any point within the universe.
Since we are both trying to make our models the most logical in the face of the unknown reality of the spatial issue, it is safe to say that our logic is different.
The logic that leads me to the hypothesis of a spatially infinite universe is that I have a problem with the logic of a concept of "nothingness". I associate nothingness with a spatially finite universe since it comes into play when the question is asked, "What is beyond the boundary of finite space?" In your model, as I interpret it, the answer is nothing, which I think you allow to be called empty space.
My definition of "nothingness", in respect to this issue, corresponds to your nothing/empty space, and I don't think logic permits nothingness or empty space.
Given all of that, maybe we could boil the difference in our logic down to the fact that your model embraces a concept of nothingness in regard to beyond the boundary of the aether medium, and my model denies nothingness and so the aether medium is infinite in all directions.