The drive system is belt driven and results in zero additional backlash. See the autofocus image. You will notice that the V-curve is very symmetrical and the "V" is nice and sharp. This means the backlash is very low and any backlash is likely from the EAF itself.
The side opposite the EAF has a standard Synta shoe/saddle for mounting additional accessories such as an ASIAir or Pegasus Powerbox etc.