Another quick update.
I've mainly been working on getting the switch insert just right. Getting clips to snap in and hold nice and tight without being a pain to install is an interesting balancing act. I also have to make sure the tabs are strong enough and won't snap off after a few uses. It has to clip into place, and be held tight so it doesn't rattle. It also has to be 3d printable! There are some pretty large constraints on printing this stuff. You can't just print any shape you want, it has to be designed to be printable.
Here is a picture of the blanking plate for reference.
Here is an exploded view of the nearly finished version.
And here is a more updated version. You can see the text is a bit bigger and bolder.