This was posted by Brian from Roon on their site 2 years ago:
”ASIO and WASAPI are different interfaces that applications can use to play sound on Windows. WASAPI is Microsoft’s current native interface for audio playback, and ASIO is a 3rd party alternative built to suit the pro audio market decades ago.
Your main goal should be to bypass the "software mixer" built into the operating system. This mixer is what allows you to hear Windows noises mixed with notification sounds, mixed with Youtube at the same time. This is convenient, and appropriate for most software, but it modifies the audio content along the way in a manner that is optimized for performance/battery life over sound quality. Not ideal for focused music listening.
ASIO always bypasses the software mixer. WASAPI bypasses it only if you choose to do so. If you want to bypass the software mixer with WASAPI, you use something called "Exclusive Mode", which means that your app takes exclusive control over the audio hardware while it’s playing, thus boxing out other apps and the software mixer. If you are having a focused listening session with an external DAC, I would recommend using either ASIO or WASAPI Exclusive mode to ensure that the communication between software and DAC is as clean as possible.”
Though no the identical situation I do use Roon and when I installed the Gryphon drivers it gave me the option to choose which one I would employ. I chose ASIO and have not had any desire to revels it that choice.