Quote - Especially when you have a UV mapped figure that's been textured right up to the edges of the UVs without any overlapping. The lower the minimum shading rate, the less likely you'll see a visible seam, which would look like a gap in this case..

Right, the space between the textures are affected, not the texture itself. I fail to see how (bitmap) texture resolution improves with decreasing the shading rate. Said another way, if a single pixel of a bitmap in shader space is broken into "sub-pixels", how could one introduce greater resolution? They're all still the same color.