How do I separate 1 Vertex that has 2 UVs? I've imported a model from MagicaVoxel, and it uses UV mapping to assign vertex colors. I'm editing it in Blender 2.8, but I'm running into the issue that one vertex has 2 UVs in the same UV map! I thought this was impossible, and I need one vertex per UV. See the image below:

Here's a video of the same effect in motion (you might need to full-screen to see the detail)
As explained in the image, selecting that vertex in the 3D viewport auto-selects 2 UVs in the UV editor. Alternatively, selecting one of those 2 UVs auto-selects the other, but the stats bar at the bottom says I've only picked 1 vert.
Question:
How can I split these type of vertices that have multiple UVs? I'd like one vertex for the light-gray UV, and one vertex for the navy blue UV. My scene has 135k verts, so I would be very grateful for a solution that doesn't require I hand-pick them.
A vertex exists in five-dimensional space, with coordinates (x,y,z,u,v), so while two vertices may share coordinates in 3D space, they can still be in different places in UV space.

Every time you create a UV seam, or have two different shading groups (flat shading), under the hood you are splitting those vertices along the seam into multiple vertices. It's confusing though because Blender will still treat these as a single vertex in many circumstances.

The way you can get around with for UV editing is to turn off UV Sync Selection:


The down-side is that only elements of your mesh that you've got selected in 3D view will show up in UV view, but this will allow you to manipulate vertices separately in the UV editor, even if they appear to be the same vertex in the 3D view.