Thanks rhome, I found it. This seems to be the only brand that actually has them posted. 3 inches would be ok behind a door but we are not going to have that much space available for it. Here are the results of my investigation so far regarding the other brands: GE customer service told me again that they are not authorized to discuss this installation as it is not approved (meanwhile I have a magazine right in front of me with several kitchens showing the same ge spacemaker m/w in a cabinet without a trim kit and minimal clearance, go figure) KitchenAid and Sharp customer service both said sure, it is ok, just keep a small gap. They also proceeded to explain that if there is not enough clearance, the m/w will overheat and shut down and we will not be able to use it until it cools off. But when I tried to get them to tell me the exact clearance required for that not to happen, the answer was to "use your common sense". That is great but if I am going to order custom cabinets based on my common sense alone and it fails me that wouldn't be very good, would it? So the choices are: install it anyway and hope for the best, forget the looks and use a trim kit or hide it behind a door and use small enough m/w that this is not an issue. Oh my, decisions, decisions...

I’m doing a renovation right now with an original ceiling height of 8’. With an added layer of sub floor, the final ceiling height is 95”. I elected to go with 36” uppers even though I want the cabinets to go all the way to the ceiling. 42” were an option, but it would result in a 17” clearance to the countertop. With under cabinet light i thought it would be far too crowded. The 36” cabinets will give a 23” counter to bottom of cabinet clearance. That seems high but it’ll give ample room for mixers, under cabinet lighting, etc. I’m also considering adding a floating wall mount shelf under the uppers at about 17” above countertop. I’d make the shelf maybe 8” deep to maintain the open workspace while adding display storage. Thoughts?

I would try to find more cab space elsewhere before I took out the window. Before you commit to low windows, see if you can go hang out in a real kitchen with them first. Some people find them extremely annoying - remember those peninsulas popular in the 80s that had the cabs hanging down over them? You'd be bending down to try to talk to your guests on the other side - same principle.

The micros in those inspiration photos are installed incorrectly. The heat/steam from a microwave needs someplace to vent, otherwise you will have damage to the microwave at minimum and quite likely damage to the surrounding cabinetry over time. The optimal solution is to pick the opening dimensions that correspond to "worst case" (largest) for the microwave(s) you might consider. You can always put one in that requires less gap distances (although aesthetically it might be less desirable). For example, if you have 2 microwaves under consideration and with clearances they need openings 24W x 16D x 15H and 25W x 14D x 18H you should have an opening 25W x 16D x 18H. This would let you put either microwave in the space.