As of CS6 it's no longer necessary to activate the AfterEffect installation on each worker. Please refer to the Adobe post here:
http://blogs.adobe.com/aftereffects/2012/06/codecs-and-the-render-engine-in-after-effects-cs6.html
A snippet from the URL:
In After Effects CS6, you can now run aerender or use the watch folder functionality in a non-royalty-bearing mode, without activating the render-only instances of the application.
In this non-royalty-bearing mode, the following codec-specific features are disabled:
- decoding and encoding (import and export) of MPEG-2 video, including formats that are based on MPEG-2 video: XDCAM EX, XDCAM HD and other formats in MXF OP1a containers, and HDV
- decoding of AC3 / Dolby Digital audio, which is used in AVCHD media
All other formats that After Effects can import and export are enabled in non-royalty-bearing mode.
To enable non-royalty-bearing mode:
- Install After Effects on the render-only machine.
- Place a blank file named ae_render_only_node.txt into one of the following locations, depending on the user account type:
Mac OS:
- /Users/[username]/Documents/
- /Users/Shared/Adobe/
Windows:
- C:\Users\[username]\Documents
- C:\Users\Public\Documents\Adobe