This is helpful and confirms my suspicions. One question to clarify your setup -- So the 4k monitor is connected directly to your mac with a thunderbolt cable,

This is helpful and confirms my suspicions. One question to clarify your setup -- So the 4k monitor is connected directly to your mac with a thunderbolt cable, one of the QHD monitors is connected directly to your mac through HDMI, and the second QHD monitor is connected through the CalDigit dock? If you don't mind, can I ask why not just connect both QHD monitors through the CalDigit dock?