Anytime you are moving from the D shape to the C shape, or back, you have that one-fret adjustment to make. I also am finding it almost impossible to get up to 60 bpm with the CAGED progressions because of the D shaped barre chord. I tried barring with my middle finger but my fingers don't bend enough that way, either. I can play the "mini" versions, but that seems to defeat the point of the practice. However, Griff is the teacher, and if he says it's okay, then I guess it must be. I am relieved to know that it's a common problem, which means that I will eventually be able to overcome it.