The High-Quality Rendering button is greyed out and cannot be set for Parts
Solution Open Solid Edge Options and check the Application setting in the 'View' area.
It needs to be set to 'Graphics Card Driven (Advanced)' instead the default 'Software Driven' setting.
After a Solid Edge restart the High-Quality Rendering Button and the functionality is available to use.
Notes and References
Hardware/Software Configuration Platform: INTEL
OS Version: 1064