Actually, WHQL certification is not required for a virtual audio driver. WHQL is only required when the driver is being supplied by a hardware manufacturer. The Digital Power Station virtual driver has a Verisign digital signing certificate which is all that is necessary from a third party developer.
We have been in contact with the Microsoft Windows 10 audio engine team. They have been very helpful and have recognized that our driver is causing a new error in their code. We have been running diagnostics for them and have provided our driver to them for collaboration.
I will report again when we have more news.