Popper concerns itself with test-ability, not truth. Something can be both untestable and true.
Occams razor says more about human psychology and beliefs than it does about reality.
In any case I was not arguing that this scenario represents the true state of the universe, but am arguing against grand parent's argument that we can conclude consciousness is physical without making certain assumptions about the nature and design of the universe, even if empirically it is our best guess.
I am not sure I'd care about the definition of "true", that does not fulfill the Popper criteria. That is the whole point of it.
Occams Razor is a tool people use to pick the best theory (in terms of size) among theories otherwise describing the same universe. These theories are otherwise identical.
The same applies to your last point: we simply pick the best theory at hand, and that argument does exactly that.
Occams razor says more about human psychology and beliefs than it does about reality.
In any case I was not arguing that this scenario represents the true state of the universe, but am arguing against grand parent's argument that we can conclude consciousness is physical without making certain assumptions about the nature and design of the universe, even if empirically it is our best guess.