1. Previews, rather than what is clearly a bunch of actions dressed up as a filter.
Well. . .I guess you didn't get the part about viewing an image on screen -NOT- being a good indicator of how and how much to sharpen? While we do have previews now in PhotoKit Color 2, the next version of PhotoKit Sharpener still won't have previews.
One might be able to get a better guage of how much to sharpen if you view your images at a 25% screen zoom in Photoshop, but it's not precise. Photoshop's screen views simply are not useful for real eval of sharpening. There are arguably 72 pixels/inch on a computer display. The Epson are arguably 360ppi (the real resolution is another debate). So, how ya gonna see 360ppi on a 72ppi display?
When you zoom into 100% the image is no longer anywhere near accurate to size. Look at an image at 200%? Pure science fiction. No printer could resolve what the screen is showing you.
The actual resolving power of the human eye with 20/20 vision is typically considered to be about one arc minute or 60 arc seconds. A rough approximation, at a distance of one foot, could be considered to be about 360 ppi for high contrast line pairs. The resolution requirements go down as the contrast reduces.
But a computer display, at the same distance is still 72ppi.
See the disconnect? See why you can't use a computer display to accurately evaluate sharpening?
So, what's a preview gonna do for you? Not a lot. . .
As far as Mitch matching PhotoKit Sharpener. . .well, he's tried to copy it right down to the terminology. But he still doesn't know the magic numbers. He hasn't done the extensive testing. On the other hand, Bruce Fraser, a noted and respected author and imaging expert HAS done the testing. . .perhaps that's worth something? His actions are error prone and his scripts are un-batchable from Bridge. So, workflow wise, you're still back to trying to delude yourself that you can "see" what you should do to an image on a display.
If it's all science, why capture sharpen on a layer and allow you to adjust the opacity/layer mask to taste?
Flexibility. . .