The folder structure is 4 chunks à 1 character + / sha1 hash as set in the FileSystemStorage class.
So you had to adjust the method to get the path a little bit
from
$resourcePathAndFilename = Files::concatenatePaths(array($this->options['basePath'], wordwrap($tokenData['resourceIdentifier'], 5, '/', TRUE), $tokenData['resourceIdentifier']));
to
$resourcePathAndFilename = Files::concatenatePaths(array($this->options['basePath'], wordwrap(substr($tokenData['resourceIdentifier'],0,4), 1, '/', TRUE), $tokenData['resourceIdentifier']));
The folder structure is 4 chunks à 1 character + / sha1 hash as set in the FileSystemStorage class. So you had to adjust the method to get the path a little bit from $resourcePathAndFilename = Files::concatenatePaths(array($this->options['basePath'], wordwrap($tokenData['resourceIdentifier'], 5, '/', TRUE), $tokenData['resourceIdentifier']));
to $resourcePathAndFilename = Files::concatenatePaths(array($this->options['basePath'], wordwrap(substr($tokenData['resourceIdentifier'],0,4), 1, '/', TRUE), $tokenData['resourceIdentifier']));