Taping or not taping, I have gotten cracks or lifting of the tape both ways. Homosote can be dynamic. The leveling/feathering is more to achieve a flat surface. Ground cover hides cracks. Tape can also be pushed up and hump along the seam, even push up ground cover to where you can detect the seam. I no longer tape Homosote seams. Your experience may vary.
For two rail use, some irregular Homosote can be a challenge. Skim coating for flatness may be essential.