Maybe it is personal preference, but I like the Righthand Nav bar the way you've got it setup for the Internal Plugins which uses the expandible format that is setup in nav.adoc.

I realize that for some reason when we select an external plugin, the right hand navigation bar changes.
Is there a reason for this? Isn't there some way to keep the nav.adoc version here? (prefered IMHO). Is there a reason to show this less versatile nav?

Note. I will be pushing the Simplified Navigation shortly, so wait a bit on this problem. Thanks.