From the documentation it appears that you can write to any file if you have filepicker.picked it. Is this true even if the file was outside the browser file system sandbox? For example I select /home/me/myfile.txt ? Assume the file has write permissions for anyone. Can you write directly to myfile.txt? Or is a push to S3 + download involved.
There are some files where it is not possible to write back. Local files is a good example of this. We throw a 409 HTTP error for files like that. You can of course write to the s3 copy.
