A new subdirectory of APPDATA\Mozilla\SystemExtensionsDev which causes the Mozilla directory to be left and a new Mozilla directory at LOCALLOW\Mozilla. Both directories are empty. This will be addressed in the next release.
You can test the upcoming version of the launcher here: Firefox Portable Launcher 2.1.1.
MD5: 73aa27297d170a8415f9025d5a8785c7
UPDATED: 2017-12-21 - Added fix for updates empty directories.