Aside from the fact that cheap stamped cogs are not as round/true/hard as a properly machined cog like a DA the OEM assembly process is likely to have little to no grease applied to to the hub & lock-ring threads and unknown force applied to the lock-ring. Removing both when nearly new to assure proper lubrication will prevent difficulty in replacing a worn cog in future. Might as well install the DA at that point, torque all properly and have at it.

-Bandera