So, in hindsight, it would have been best to have a 24" tall over-the-microwave cabinet. Why? Because if we had attached the microwave to the 22" cabinet, future owners shorter than us would have been upset as they reached longingly to reheat food, or bought a ladder. However, Brent is nothing if not creative in fixes, and we were able to use the extra filler strip we had leftover from the cabinet install to make a transition from the cabinet to the microwave.
One problem...the screws that came with the microwave were too short. By a lot. Big shout out to Boltdepot.com! We were able to order the proper screws, and they arrived very quickly.
Then, Brent just had to extend the blocks that went under the cabinet for mounting.
After that, he installed the mounting plate.
Ta da! First appliance was in - and at a very user-friendly height!
We think that it was infinitely better to have the filler strip at the bottom of the cabinet so that we could maintain a uniform look across the top of room of cabinet-to-cabinet at the top. Can't wait to get the rest of the appliances in!