Yes, ive tested it , a lot. works 100% to dev_blind/dev_flash2, and it works until 100% on all other paths (with deletion), and it works with background downloading to hdd to 100% with 99% error.That might sounds a stupid question but well : are you sure that device_path means the complete location where the file will be downloaded (full path) ?
The reason i dont think its related to logical scheme is i can put anything in there.
Test it out, its 2 xmls that work on OFW.