I hear ya on the variable thickness of the cord. It can be aggravating. Focusing on tightening the loops of the wrap will help, and you might give the wrap more coats of sealer (shellac in this case). It'll help fill in between.
If you want to try a cord that's less wild, Ben Tendick has done some neat wraps using bamboo cord, and Tai Goo has used cotton cord as well.