[iliis]

Well, okay. Technically you're right ;) But what if you count any movements that are followed by another movement of the same face as a single step?

[Someone]

The set of possible configurations would split in an even and an odd set, so there would be configurations that can’t be solved in God’s number of moves.

(AFAIK, we don’t know God’s number if we count moves that way. I would guess it’s larger than 20)