Hide Seams Layer
In the layers panel, there are options for adding a paint, fill, smart material, etc.
I would like to suggest adding a "Hide Seams" option that would create a paint layer that is set up to paint over seams.
But, I'd like it to be smarter than manually creating a paint layer where I have to manually change all of the channels to "Passthrough."
When I do it manually, there doesn't seem to be a way that I can create a brush that includes all of the effects that have been layered on the object.
So when I begin to paint out the seam, it acts like an eraser for everything else like dust, grime, stains, etc. and there is no easy way to recreate those effects so that it matches everything around it.
I think it would be difficult to create a special Seams Brush that incorporated the percentage of settings for all the effects layers below.
But I do think it might be possible to have a Seams Brush that could paint on the base Fill Layer to hide the seam with the base fill that is below everything else.
I tried to use a paint layer just above the base color fill layer, but I couldn't get it to do anything. I could see that I was paining on the layer but it wasn't affecting the fill layer below it. In fact it wasn't affecting anything that I could see.
An option to create a new channel with all channel blending modes set to passthrough would be good.