I don't know what the rule is on this, but we put our 4" cans with the edge closest to the cabinet over the edge of the counter. That way, they shine right in front of you when you are standing at the counter. A 6" would get pushed back farther if you use the edge. Stand at a counter where you would work comfortably and look up. My thought is that you want the center of the light just in front of you and hitting the counter in front of the upper cabinets. To close and they wash the cabinet more than light your work space and too far back, the center of the light will hit your head rather than toe work area. Make sense?

Take out oven wall so you just have an L and not a U. Put ovens at right side of sink wall, with pull out pantry (9 or 12") between ovens and wall. Delete ridiculous bended island. Instead create new island facing fridge/range wall. Put prep sink in it. Turn cabinet at the bottom end of it to face cleanup sink for dish storage. I would make the current sink window 3 windows so as to echo the DR windows across the way, and make them as large as possible while still being centered on the wall. As is, the scale of the one little window is kind of pathetic and jarring (sorry, no offense) when compared to the DR windows, and I think you will notice that in real life. I would also the windows down to the counter. In this layout you could swap ovens and fridge, but I would only do so unless you access the fridge way, way less than the ovens while prepping/cooking a meal. The layout I described is basically my layout, and I much prefer the fridge closer to the cooktop, island, and perimeter (for snackers) of the kitchen.

I would try another full height, shallow depth pantry cabinet, rotated 90 degrees to it backed into the other pantry cabinet. Same thing with shallow bookshelves and with angled corner shelves. Also maybe try two full height, single door pantry cabinets or slightly smaller full height pantry cabinets with wine bottle cubbies between them on one side of the ref. It's really hard to tell aisle and such from a perspective drawing - they can be really misleading. So take this will a little salt. It looks like you have about a three foot aisle between the fronts of the pantries and the peninsula. Even if you get a counter depth ref, it will still come out into the aisle about six inches including the doors and the handles. Plus another inch or two will go to adding decorative panels on the end of the peninsula cabinets and the countertop overhang. So you're aisle may turn out to be more like 28" there. Can the ref be maneuvered into or out of its place without removing the peninsula? Can you open the freezer completely? Are you ok with having to close the freezer door, walk by it and re-open to reach something on the other side?

Frankly I'm no fan of a U shaped kitchen because two corners are one extra useless corner. Working off of Mama's excellent plan, I turned it into an L shape. 1. I moved the fridge to the opposite side. The reason I did so is your mudroom and your pantry are on that side. Coming in with groceries would mean lots of steps back and forth to put foodstuff away if your fridge is so far from the pantry. The same holds true when grabbing food to make a meal. Great exercise but really do you want to walk across your kitchen to get stuff from the pantry and then back again across the kitchen to get stuff from your fridge? 2. I moved the microwave shelf to that side too. I did it since it's closer to the fridge and it's out of the cooking zone. 3. I widened your island. 4. I added a 42" dish drawer facing your dishwasher so it's easy unloading to your dish drawer. 5. I moved the trash drawers to next to the prep sink. You didn't mention if you plan on having a disposal unit in your sink? I have a prep sink and a cleanup sink and put a disposal unit in both. They're not too expensive and I felt it was well worth it. I'm also planning on putting a small trash can UNDER my clean up sink. Most trash is generated by the prep area, so the trash under the clean up sink is only for the occasional food stuff that can't go down the disposal. 6. Next to your air return, I added narrow shelving. This can be open or closed and is good for storing stuff one can deep, so would be good for stuff you use more frequently like cereals, etc. One other thing I noticed not related to your kitchen but your pantry/powder room. You don't want the door to your powder room opening into the powder room because think of how you will need to be a contortionist to try and get around the door to use the toilet. Get a pocket door or have the door swing out. Additionally I would not angle the corner where the sink is in there as it will feel quite congested as it's a small room already. The space out of the pantry is minimal but will make the powder room feel larger.