For those who are actually interested in this, here is a quick/easy focus peaking accuracy test with the A7R II and a wide angle lens. Focus peaking was set to low. I did it with live view setting effect both on and off, but the results were identical, so there’s no point in posting more than one set of images. The results were also the same using the EVF instead of the LCD.
This is the full scene, and focus peaking says the test chart is in focus:
This is a 100% view of the test chart, which is clearly out of focus:
This is a 100% view of the test chart when properly focused:
Clearly not everything that focus peaking lights up as in focus is actually in focus, so for me it is not accurate enough to be relied upon.