The minimap sprite opacity is set to “additive” rather than “summed” or “normalized”, meaning, two overlapping sprites at 50% opacity create a sprite that is opaque, rather than the correct setting of 50%.
What this means in terms of gameplay is a map that is visually difficult to parse. I recognize this issue as a game developer because I have to deal with it all the time so I think this was just overlooked while making the shaders.
https://imgur.com/a/geEQ22p