I've made great progress over the past several days!
Saving of palettes was completed (which I think I posted about already), and I have full camera rotation and zooming working in the Voxel Editor. I need to do some more testing, but I also have the new editing functionality complete for the Voxel Editor. There are now three modes, Attach, Paint, and Erase, that work similarly to MagicaVoxel while in voxel mode. I took some quick screenshots to show them in action. :)
I am planning to push another release sometime this coming weekend that will include these changes. There are still a lot of convenience features I'd like to add to the Voxel Editor, but I think this will be a good base to start with!