Follow-up Summary: Working with this customer we did find that the Graphics Master circuit has a temperature dependency due to a current-limiting resistor in the Vee circuit. We will update the Graphics Master Vee circuit to eliminate this problem. Our latest products do not have this issue.
Contact us if you think this issue is affecting your Graphics Master application!
Note that the Vee requirements of most passive displays do change with temperature, which must be compensated for programmatically. In this case, however, the Vee output from the Graphics Master was changing with temperature, which was our issue to resolve.