You can greatly simplify the animation of any rotating object by going to its properties and right-click transform>rotate>convert driver to and change the bone to "Euler" instead of the default Quaternion mode   You can set one key at frame 0 and another at the end for (number of turns you want X 360°) and A:M will do the whole thing for you. This should eliminate the need for the MUFOOF technique   OR... you can set frame 0 to 0° rotation and frame 1 to anything, say 90°, and then