I also found this bug using the HWE stack.
System76 Lemur 6 (i7-6500U CPU Skylake GT2 HD520) running 16.04.3 LTS
Flicker occurs on return from black monitor to screens after screen has been turned off. Worse with a second monitor plugged in. Resolution is to click on the workplace switcher and then select a screen (1/4).
I also found this bug using the HWE stack.
System76 Lemur 6 (i7-6500U CPU Skylake GT2 HD520) running 16.04.3 LTS
Flicker occurs on return from black monitor to screens after screen has been turned off. Worse with a second monitor plugged in. Resolution is to click on the workplace switcher and then select a screen (1/4).