If you're showing the 430W's flight plan on SkyView's map (this is a new feature), SkyView will generate its own approaching waypoint annunciations based on the 430W's waypoints. This may not identically concur with the WPT annunciation on the 430W, but it's providing essentially the same information.
You don't really need a separate VLOC/GPS with an electronic HSI, as it's always apparent from the HSI info area whether you're looking at the NAV radio (VLOC) or GPS side of the 430 (or SkyView's flight plan, if you're using that). With an older mechanical HSI you can't tell what it's displaying without an indicator. You can control which side of the 430W you're looking at on SkyView from either SkyView or the 430W directly, depending on how you have the AUTO SWITCH option configured. See the SV-ARINC-429 Installation and Configuration section of our installation guide for more details on this.
We don't show TERM/APPR scaling directly, but we do show the numerical CDI range when in those modes. That's not exactly what you're after, so you might want to have an external annunciation in this case. We'll look into improving the annunciation here (no promises).
SkyView doens't show the MSG annunciation from the 430 currently.
All that said, instead of actually building your own annunciators, you can use extra EMS general purposes set up as contact inputs and turn them into annunciations on your EMS page.