In the past I did this, not on the EOAT, though there's nothing wrong with that approach; but, with two pieces of aluminum on a bracket mounted across the conveyor. I took the robot and ran the parts up and down 4x for the hinges to be flexed. The parts had wide flaps on them so they were flexed a high degree. I figured the 4 movements were not necessary but I was able to do this without extending the cycle time of the press.
I did run a PP/PA6 part once that we didn't flex the hinges on because it was used one time and oce the flap was latched down; it wasn't designed to be opened again.
Rick