I think you can just leave it. The bottom of the cabinet is unfinished and nobody cares, right? This is pretty much the same thing.

I do think it's worth trying to do a sliver under the micro-hood, though. That will be noticed!

(Love the tile--perfect choice!)

Thanks the tile was meant to accentuate the difference in the cabinets and the counters and tone it down a bit from the honey. My concern is the shorter side is essentially an accent wall its center kitchen center house and im worried whatever i do on that wall will show throughout...

For reference the wall measured out 5/8" but i leveled the counters and tile so the bottom was a flat edge and the tiles were 100% level across so my 3/8" gap at the top is a true 3/8" left to right across 96" of counter/stove

Also yes I do plan on putting tile above the Microwave space i just didn't do it in case i did some kind of accent tile

If people are sitting where they can see it, you COULD throw up a strip of oak molding stained to match.

You could try painting that sliver of wall a color as similar to the tile as you can get, then the eye just might pretend there’s no gap