HQ Player - a few questions

Likely it does, since Spring 2 does (Spring 1 doesn’t).

DACs claim to support also 48k-base DSD if they support 48k-base PCM. Most ASIO drivers on Windows filter these out. When unchecked, HQPlayer also filters out 48k-base DSD rates even if DAC claims to support it (most actually don’t). Checking the box actually let’s these 48k-base claimed rates to become visible and available.