That's not a bad idea.  Our plan, though, was to write this to match the conditions inside [`setUpConversion`](https://github.com/virtual-world-framework/three.js/blob/single-axis-up-conversion/examples/js/loaders/ColladaLoader.js#L4719) and [`fixCoords`](https://github.com/virtual-world-framework/three.js/blob/single-axis-up-conversion/examples/js/loaders/ColladaLoader.js#L4750).  Perhaps the original author wanted to make sure that the functions returned properly if somehow `convertUpAxis` became undefined?