I did a bit of research and the WASAPI is a Microsoft standard to output to usb, the exclusive part excludes the system sounds/notifications, whereas the ASIO seems to be still PC specific but NOT Microsoft and generally considered better.
Also the WASAPI output in MB limits the output drivers and cannot be configured. The ASIO output allows me to use a updated device driver and also allows the output to be set to "Stream DSD data as PCM (DOP)" which I believe is the correct way to stream the DSD data to dac.

Ouch. WASAPI is actually the "new" default Microsoft audio API introduced with Vista and supported by Windows 7+, to replace the deprecated DirectSound and nothing to do with USB per-se.
It can be used as WASAPI-"shared," where it can be used simultaneously with system sounds and and passes everything through the Windows Mixer, to be resampled/handled/etc at will by that component. As such, it is NOT bit-perfect. Fading and other DSP effects can be applied.
When it is used as WASAPI-"exclusive", it retains full control over the path to the audio device, by-passing the Windows Mixer and passing the audio as-is from the source file to the drivers. Like ASIO, then it is also bit-perfect. It will stream a DSD source as PCM, but ASIO "seems" to be required for non-PCM playback of the original bit stream.
There has been a lot of discussion here (e.g.,
https://getmusicbee.com/forum/index.php?topic=30461.0) about MusicBee and DSD (use the search box
https://cse.google.com/cse?cx=426af386625354430#gsc.tab=0) and frankly the results are murky and unclear. We need some DSD fan who actively uses MB for these files to provide us with a full "Tips & Tricks" post that "explains all"--DSD playback using PCM. DOP, or Direct with both ASIO and Wasapi-exclusive models.