I'll pick up the thread here...
I want it to be clear that I don't think the Platonic view is the last word on everything in Physics. Instead; I feel that the idea of a mathematical universe is an essential piece of the puzzle to understand. It is fruitless to debate the notion of the pre-existence of the orderly form that appears in Math. The point is instead the unvarying nature of some aspects of mathematical reasoning, or persistent objects and principles within Math - which come out the same regardless of how you get there.
These patterns appear in nature, as well as in abstract studies like Mathematics. It is freely admitted that some attempts at a constructivist formulation for Math have been disappointing, but I see nothing wrong with the basic mechanics of that approach. My guess is that there is a constructive proof possible for any mathematical statement that is generally proved in other ways, but I could be wrong. The nice thing about constructive proofs is that they can be turned into computing algorithms with great ease.
But as many have pointed out; Physics is all about how natural law and the universe unfold whatever underlying principles exist into observable form. I think the underlying principles are identical however, and it's a matter of whether concrete or abstract information is desired. I may talk more about this idea in the page Zeeya Merali and FQXi have opened up for discussing Dimensional Reduction in the Sky, because of its relevance to the topic of that paper.
Have Fun!
Jonathan