Callback File System has been updated to version 6.1 (build 178).
This version includes redirection of file requests to the local file and the local cache for remote files. These two features complement each other and let you provide files to the user faster, if you have those files available on the local disk.
Please also check the announcement about original version 6 release. Version 6 includes improved compatibility with Windows 10, and if you have not upgraded yet, now it's right time.