SeattleDucks, thanks for the image.
Coincidentally, I have removed two major sharpening steps (the 2nd one just this week) since getting the 645z as being more destructive than helpful to my Pentax images. The last few images I have processed received only a modest wide radius treatment (amount 9) for contrast and Bicubic Sharper (if you can call this sharpening). No sharpening in ACR.
Deconvolution sharpening (formerly known as capture sharpening perhaps coined in Bruce Fraser's book, first edition) provides only a visible difference in the size image I use viewing at about 3 inches (no hyperbole) vs. the method above. The work involved in optimizing the capture/deconvolution sharpening for each image for this small difference may not be effort-effective for many, images printed at 54" notwithstanding.
Have you determined your settings above as a default LR?
Regarding diffraction, I've seen some apertures mentioned in this thread in conjunction with nameless lenses that I'd like to get more info on. Although I use f16 without trepidation, I haven't noticed that I need to stop down for any reason other than DoF purposes with the lenses I own, 28-45, 55 (kit lens), 120 A, 200 FA & 45-85 FA. Maybe I haven't been observant enough. Using the Cambridge in Colour diffraction calculator and putting in enough pixels to produce a 5.3um pixel size matching the 645z pixel size per the suggestions of the members there, it appears that f11 is not diffraction limited whereas f16 is. This doesn't mean that diffraction isn't present at f11 or f8 but again, it's all of that work....
I noticed a trio of iconic images hanging in your living room/den. If only I was allowed to hang photos.
My gal, the decorator, believes in more traditional art objects.