"Significant improvements have been made to Mac client performance across the game". Oh, yes! What exactly were these? The Mac client was ok for me, using Mojave 10.14. No problems, until you swapped out the rendering system for something which performs significantly badly on a top-spec iMac! Whoever wrote the software doesn't understand Mac user interface standards, and certainly didn't test them properly.
On the latest patch:
1. The ESO client results in an [Apple Mac OS] exception crash report whenever the Quit function is taken!
2. Selecting "Play" from the Launcher, launches the ESO client in a state where a flashing cursor indicates readiness to accept input for the password, but results in a beep if keyboard entry is attempted. You have to mouse click twice to get this field into a state where it can actually accept input!
3. The ESO program is launched in Windowed [FullScreen] state which shows a menubar which contains useless functions which do not conform to standard Mac user experience. The standard Full screen [non-windowed option is not available. If the command from the Menu bar is taken the window is actually reduced to about a quarter of its beginning size without border in the middle of the screen!
4. If the ESO settings Video section is selected, you can change to a full screen non-windowed display, but this option is never remembered for the next time you log-in.
5. Video performance is still poor resulting in choppy lost frames in congested and busy scenes. This did not happen before the change to the graphics rendering system for Mac OS was changed for this ESO client. This goes along with big reductions in the quality of the graphics displayed such as view distance, distance resolution, water effects and blooming etc.
Please, swap back the rendering system to what it was before 4.20