Back when I was still an intern, I noticed that i was getting wrist pain and was instantly worries about getting carpel tunnel later so I went out and got a Microsoft Ergonomic keyboard.
I've since stuck with them and one of the things that I love about them is how they force you to use more of your fingers because it restricts what keys each hand has access to. I found that the way I typed changed, the 't', 'g', 'r' and 'f' keys I could no longer reach over with my left hand and vice versa for the other hand. This meant I had to switch my how I typed which inevitably switched which fingers I used to hit some fingers and forced me to use more of my hand for the typing (the "smear" as you call it)
I've since stuck with them and one of the things that I love about them is how they force you to use more of your fingers because it restricts what keys each hand has access to. I found that the way I typed changed, the 't', 'g', 'r' and 'f' keys I could no longer reach over with my left hand and vice versa for the other hand. This meant I had to switch my how I typed which inevitably switched which fingers I used to hit some fingers and forced me to use more of my hand for the typing (the "smear" as you call it)