Sure there could be, but that is just it, they were "too minor." Anomalies like the ones you are pointing to would not be "too minor" if they were true doubling. You would be able to see it with very little magnification. I think most of the too minor stuff is on RPMs not doubled dies. RPMs are more common than true doubled dies to begin with. I have discovered two RPMs that had never been listed before that I was given credit as the person that "discovered" these RPMs. I also have about two full tubes of "too minor" to list RPMs. Most are tilted or rotated and show extremely minor notching in one or both serifs. I keep them in the off chance one attributor will get bored one day and list a few of them. If you want easy to find doubled dies look at memorial cents from around 1997-2006. Look on the reverse. Look for minor doubling of a column next to Lincolns statue. You will also find doubling on the statue with the knees and feet. Coppercoins does list some of these, but I would bet that there are a dozen or more not listed for any given year because they are just too minor.