It's still as complicated as it was with PS CS6 years ago?
In Aperture as well as in in Capture, I just can simply copy and paste current settings to as much pictures as I want to select. Or save them as a style.
You can also select multiple images at the same time, work on the Primary Variant only and shift+click the diagonal arrow button on the tool when you're pleased with the result, which will apply the same effect to all selected images. It's even faster than copy-paste because it's one click and you see all the images at the same time.
Having a second screen helps greatly there.