MTP is miserably slow, prone to crashing, and foobar2000 desktop refuses to interact with MTP devices even via drag and drop (!). It's not a viable option for transferring music. This puts us in the awkward position of foobar2000's UPnP support being the single best way to get music onto Windows Mobile (and a highly viable solution on Android).

Using ethernet over USB-C (or WiFi for the patient), downloading playlists over UPnP is intuitive, simple, fast, and makes use of functions/software we all are already using. Unfortunately, the current behavior is to redownload the same song as many times as you tell it to, creating a new file each time.

We need some basic file collision detection; if the file exists, don't redownload it. When I download playlists from UPnP, I expect foobar2000 to not redownload songs I already have. Multiple playlists with overlapping songs should not have each conflict downloaded twice. Downloading the same playlist twice should not download every song twice; only the files that are not already on the client side.