I have no qualms with it being an officially supported plugin, however:
- I assumed from Jeff’s comment above he supports this feature in core.
- The plugin has known issues - including for the specific use case (topnav) that I’m looking to have supported.
- Plugins are more complicated for sysadmins to handle. They require ssh access to the server, are updated independently, break more frequently than core (less tests), and are a sticky subject for hosting (which plugins go for which plans).