How to prepare new stucco, for a later heavy duty item attachment?
Possibly 'Trex' block build-outs to stucco up against.  The blocks would set proud of the stucco finish surface a bit.  Secure the blocks  to the sheathing and on into a stud and or 2x4 backing.  I would cut an octagonal or diamond shaped block for appearance. Paint it the same color as the stucco. 

Another option would be a pattern of threaded rod anchors. (Sammy) Fill the thread to keep clean.