So this was posted over at PortableApps: https://portableapps.com/node/62217 by rbon (rbon?).
Pros:
* Looks like it will download in batch, in particular all the files from an individual channel
* Lots of good format options, simple UI
Cons:
* Massive program, saves large files outside the local folder
* Very slow launch process
* There's a settings panel but these get reset every time the program is restarted
Requires:
* dotNET 4.5.1
* msvcr100.dll saved to the same folder as the executable
https://sourceforge.net/projects/usnip/
Steps: Download, unzip, copy over msvcr100.dll from another program, launch Usnip.exe
Status: Portable, writes no settings. Stealth: No, writes three files to \AppData\Local\: ffmpeg.exe, ffprobe.exe, ui.exe (tested v.3.4)