It would seem to me to be to be good practise not to keep your only copy of a file in your development working directories.
Whenever I create an image/sound/data file I always have it backed up outside of the B4A environment, either within the environment of the application in which I created it, or if there are lots of files and or downloads, in a separate resources backup file for the application. And at the end of a day or appropriate time, this gets copied to another drive or somewhere in the cloud for safe keeping.
I like the ability to be able to remove a file from the working environment without having to do it manually, and if I make a mistake, I just copy it back in.