According to the team, the SpatialBiz plug-in should be able to read internal features by default. We're less certain on the GE one, so it might be worth confirming with GE Support Central if you wanted to go that route instead.
There wasn't anything specifically on internal features in this article: FME and Smallworld Configuration Options, but perhaps it'll provide some more context if you hadn't seen it already. Hope that helps a bit!