Okay, I am working on a level that has a "targetheight" field instead of a "levelexit", and WOG naturally cuts right out of the level when you're done (rather abruptly). I tinkered around with adding cutscenes to have it fade out more, and found that these lines in the island1.xml.bin file have the desired result:
<level (id) (name) (text) (ocd) cutscene="levelFadeOut,x,gooTransition_out" />

This works fine. However, I'm not sure what to put in my addin.xml file to achieve this. I would think the following code would, but it doesn't:

<level skipeolsequence="" cutscene="levelFadeOut,x,gooTransition_out">
 
  ...
</level>

Any thoughts? Am I doing something wrong?