You have, of course a point, here, which is physical again. The question is, whether the BU or Lorentz aether theory are really different physical models or mere philosophical interpretations of (special or general) relativity. In the former case, there must be predictions for observable facts about nature, that can decide between the one or the other (spacetime) model, and then it's physics. In the latter case, it's a personal decision, which philosophical or metaphysical interpretation I follow, because the models are all equivalent to relativity. Then it is not (and imho should not be) an allowed topic in these forums!