Noticed that when I start photoshop or any software that runs the dGPU the screen will sometimes (not always) flash black and sometimes twice to the point where photoshop will "encounter a problem with the gpu" and will disable gpu acceleration. If photoshop is open this flash will also occur when the machine wakes from sleep (not an issue if a dgpu software is not open in the background on wake. Lots of threads about this across multiple generations of Macs over the years. I have has the hardware checked for a separate issue at the apple store and no issues. Hoping Big Sur might fix this.