Hello RAZD
I note that you have not provided an alternative definition for macroevolution to what I presented to you.
I did not give that a lot of thought before I replied. While I may not agree with your definition to varying degrees, I can work with it for purpose of discussion.
That there is no barrier is demonstrated by convergent species, like the sugar glider and the flying squirrel: nothing prevented them from evolving such similarity to fill a similar ecological niche.
We still do not see any evidence that they broke out of the niche went beyond it in an evolutionary sense as Darwin imagined would happen with the flying fish. He imagined it might have been modified into that perfectly winged animal. In this manner the gliding frog, snake, lizard, fish, mammal, and marsupial all share the end point, in that way these creatures are failures of his theory to substantiate macro-evolution.
Darwin
seeing that we have flying birds and mammals, flying insects of the most diversified types, and formerly had flying reptiles, it is conceivable that flying-fish, which now glide far through the air, slightly rising and turning by the aid of their fluttering fins, might have been modified into perfectly winged animals. If this had been effected, who would have ever imagined that in an early transitional state they had been inhabitants of the open ocean, and had used their incipient organs of flight exclusively, as far as we know, to escape being devoured by other fish?