Seems difficult to be able to tell the difference between remnant planchet roughness, and ordinary nicks and scratches. I've seen tons of MS coins without any remnant planchet roughness, so I am not completely sold. Even if it is already on the planchet, it's not attractive and doesn't deserve a super high grade for that reason.
There are very few MS Jeffersons that have "zero" planchet roughness, even the war nickels made from a silver alloy usually have some on the jawline. As for planchet roughness affecting the grade, there are many that agree with you, but not the TPGs. I think it should be relegated to strike. If the coin is well struck but still has some planchet roughness, it would seem punitive to cause it to prevent a top grade, IMO.
I grew up being told the tiny marks on the face are called chatter marks that the strike did not remove. Sounds like planchet roughness is the proper term.