Too me this whole issue is totally mysterious.
I’ve never had such problems before upgrading to Windows 10. Yesterday I’ve spent hours to push the latency back to < 1.000µs (DPC Latency Checker as monitor) where it was as I’ve setup this machine back in 2009. I deactivated almost any device driver, stopped every application and program in the task manager and finally booted using the BIOS defaults. The latency stayed completely unchanged. 
Only changing this FW buffer made an audible change to the better (though it was a shot in th edark since both of the “required” conditions weren’t met).
Btw, I haven’t even played with Cubase yet (means any ASIO specific stuff). To me it means, it is FW-releated and therefore could be addressed with the drivers.
someone