S7 edge exynos here on nougat 7.0 … my backup is in emulated/0/storage/dos/magicbox/ (moved the folder from ibside the app )
So far 0 problems… I installed and uninstalled the app once just for trying the backup and it worked ok… the only problem was that the game links on my android desktop dissapeared when I uninstalled the app and the backup wont got em back… 67 icons on 12 folders :p
Be careful with storing in /downloads… I think some apps like ccleaner by default clean that folder when performing device maintenance… I had problems in the past because of this.