Unfortunately, I haven't moved over to WebSDK yet, and that plugin isn't one I use in the regular implementation, so I don't know how much help I will be...
However, seeing that the December update, as you said, indicates that the code now works with WebSDK, I would add the code to the WebSDK plugins area, then map the various values to the WebSDK data stream... but that's just super high level, since I don't have any practical experience with the SDK.....
If you aren't already using it, Acronym has an extension that will make the WebSDK interface more like the standard client side Analytics implementation where you add items to "eVarX" or "eventY" and it will do all the mapping for you to the Data Stream.
Here is a webinar I help to host about the plugin: https://www.youtube.com/watch?v=k7re4vxZBVk
Good luck!