Here's a small modification that will allow you to limit help topics on the new ticket page to certain users and/or organizations.
NOTE
You will need to alter the help topic table using the sql file (https://github.com/Micke1101/osTicket/blob/Help-topic-limitations/help topic db modifications.sql) and this can make it so you won't be able to upgrade once a new version is released unless you remove the 2 columns that are added (islimited, limitations).