JRiver allows you to configure itself to scan for music library changes for auto import.
One workaround on the PC is to use iTunes to maintain your main music library. So you can still use it to send music via Airplay to your Airport Express (not DSD tho).
JRiver can read from the same library (plus another folder for your DSD stuff) when you want to play DSD.
On the Mac, I use Audirvana/PureMusic to add DSD playback to my iTunes.