To avoid having too many exposed reference ports in a compound, you can use a Get Data as a kind of passthrough node:
In this example, the name of an attribute is passed through:

I’ve seen a few customers reporting that they put .xsicompound files in the Data\Compounds folder of a workgroup, but the compounds don’t show up in the Preset Manager.
This can happen when the compound doesn’t specify anything for Category or Tasks. From the docs:
If a compound is exported without a category or task, it is not available in the preset manager or nodes menu. This allows you to create utility nodes that perform specific functions inside other compounds but that are not meant to be used generally. You can add such nodes to an ICE tree using Compounds Import Compound or by dragging the compound file from a Softimage file browser or folder window.
Here’s a quick review of the Category and Tasks values:
Some interesting-looking voxel videos and compounds from 2nd reality on Vimeo
Haven’t had a chance to check them out myself yet…
Here’s the most recent video.
I’d recommend going to Vimeo so you can see all the vids and download the related compounds.
In this video, I show how to package a collection of ICE compounds as an addon (.xsiaddon).
The compounds I use are by Piotrekm.
In this video, I look into downloading and installing ICE compounds (.xsicompound files):