Yeh, it's an open rack (just the 4 corner posts with shelves and bracing) designed for this stuff,.  There's no back or sides on it and the shelves are made of 1 1/2 wood slats with 1/2 spaces in between for air flow under and above.  I made it tall and divided up the shelf height so there would be room for different (larger) toaster over & microwave when it came time to replace them.
That liner looks interesting.  Will definitely work better than my foil fix, since you can just lift it out to clean it.  I saw that Beville makes a 13" pizza stone for almost $50.  I'll shop around (lots of dubious quality out there), but will definitely get a stone.  It will be nice to make individual pizza crusts and freeze them, and not have to fire up the big oven.
I was looking at the model that's also an air fryer.  I've wanted (but certainly not needed) an air fryer but lack the room for it.  This would be both-in-one.  Most people who have an air fryer really like it.  Gotta think about it.
Thanks for all the advice!  (You, too, Pinky!)
Keep it coming!!!