I think HFS will be very flexible with adding access(rule) to files or folder , for example:
---rewriting file "A" for account AUSER
or
---rewriting ONLY file "B" for all accounts (or for guests(or guest accounts))
(like Easy_File_Sharing_Web_Server_4.0 )
that's mean all files and folders (also accounts) being with rules.
In future - adding rules for creating folders and deleting files also.
For example, that feature creates hosting server from HFS
PS also rules might be for speed - downloading, uploading and much more!
What ideas?