"The problem with the W4S are the proprietary drivers needed to run on the source machine vs. the native OS drivers used by Ayre/Wavelength.
Changes in operating system framework may require these drivers to be updated which could become problematic."
I personally wouldn't really consider this a "problem." You could say the same thing about device that a computer uses which requires drivers. Every single PCI/PCIe sound card, graphics card, network chip, ... all fall into this category.
Sound related OS updates that require driver updates for a dac are going to occur few and far between, if at all, and if/when they do happen, assuming W4S is still around, it would be pretty safe to assume that they will be able to update their drivers.
