You don't have to install the iAssist Server Daemon. Instead, download iAssist and allow it to update (so that it downloads it's modules from the Maxum server). On your workstation, open the folder "/Library/iAssist/Modules/NCFastCGI/" and you will find the NetCloak enabler in a ".sit" archive, which you can copy to your server and configure manually.
However... Maxum very strongly recommends using the iAssist installer, and running the iAssist Server Daemon on your server at all times. The server daemon is small, uses very little CPU and memory, and will not interfere with any other existing server process.
It is important to note that the iAssist server daemon only enables the iAssist client to perform actions remotely, never taking action itself (with the exception of restarting failed applications that you have told it to monitor). It will do nothing unless you explicitly perform an action in the iAssist client. So, for example, if you prefer not to use iAssist's Web server tools to manage your server, the iAssist server deamon will not interfere with whatever server management tools you are using.
At the very least, the iAServerDaemon can be used to monitor NetCloak and make sure that if it quits for any reason, it will be restarted. The server daemon can also provide this service for other server processes, again without interfering with existing software. And we strongly suspect that you'll find other iAssist functions useful for managing your server in the long term.
iAssist performs many functions, and it's capabilities will continue to grow over time. But you choose what functions you want to take advantage of, and which you ignore. Rest assured that the small, lightweight iAssist server process will not interfere where you don't want it to. There is no reason not to take adcantage of iAssist, even if it is only to simplify installing and maintaing NetCloak.