I am thinking of using the 1x1 squares along the bottom edge with a 1/2" matching travertine border on top and then the 4" diagonal above that. Not sure what to use on the bar though, as it is 4-1/2" so nothing fits just perfect.

You may not see what I see Annz, lol. If you have enabled this feature in your preferences, there is a small check box under the posting box which reads: Check here if you would like post replies emailed to you. Please note that you must enable this feature on your Preferences page by checking off 'Allow other users to send you email'. If you have the feature enabled and you check the box that is offered to you, every post to that thread will go to your email box. That is what I mean by "subscribing" to a thread. The problem is that once you sub to a thread, the "preview post" button moves down and in it's usual place you get a highlighted button that says "click here" followed by: if you no longer wish to receive notifications for this message. After writing a post I hit the first highlighted button under the post box by rote. Sometimes, that first button gives me a preview of my post (if I am not subbed to that thread), other times (if I am subbed to the thread) the first button merely unsubs me and takes me back to the general forum. Then, if I am lucky enough to realize I did not post my message, I have to go back, recover the post, and submit it. The problem is simply that having a key button (the preview post button) move around, causes me to frequently do something I did not intend to do. Maybe it's just me and my half-heimers but I've never had a moving button on any other forum and it's driving me nuts!

Re-staining :/

Your contractor's suggestion is accurate. Microwaves tend to have shorter lifespans than ovens, so when the microwave dies, you'll either have to replace both (since it's one unit) or have a working oven with a dead microwave, and buy a countertop microwave until you're ready to replace the whole appliance. One consideration is that separate appliances will have different electrical requirements than a combo appliance. As far as the features you mentioned, all of it depends on what you like to cook and your cooking style. Of the features you mentioned, I think that steam is the only one that you could possibly regret skipping. The others are convenience or tech for tech's sake IMO. Steam: there are a lot of in-depth discussions on steam ovens here on Houzz so I recommend digging through some of them and watching some demos on YouTube. Do you like steamed vegetables / fish / etc? Do you reheat lots of leftovers? This seems to be where steam excels. I've never used one myself, but there are some super talented cooks on here who rave about it. If you do want steam, see if you can plumb the water line so you don't have to fill up canisters. Air Fryer: in general, air fryers are just convection ovens with a higher fan speed. It's still a bit new to full size ovens, so there isn't a ton of info available. I know Reviewed had an article about a Frigidaire range with air fry, and it looked like the food came out pretty unevenly cooked. But one review is hardly a representative sample, and I take Reviewed's reviews with a grain of salt anyway. I "air fry" breaded chicken in my regular convection oven all the time by putting the chicken on a baking pan with a rack, a light spritz of olive oil, and convection mode. Not sure how different the results would be with a dedicated air fry mode. Seems like a nice-to-have, but I wouldn't base an entire purchase decision around this one feature. Wi-Fi: If you're leaving the kids' soccer game, you could turn the oven on from your phone so it's preheated and ready to go when you get home. Could be convenient since newer electric ovens with a hidden bake element take 15+ minutes to preheat. You could also connect it to your voice assistant, so you can ask Alexa/Google/Bixby to set the oven to 400deg while your hands are dirty with raw chicken for example. Camera: I haven't heard of this inside the oven yet. I don't know why this would even be a thing. If you're cooking something in the oven, you have to be home anyway, so just look through the window! I know Samsung has a camera in some of their fridges, and that use-case seems a lot more logical to me than a camera inside an oven. Also seems like the lens would get dirty/greasy and the image quality would deteriorate (just imagine how dirty an oven window can get). It would also help the forum if you can tell us more about your budget and what you usually cook. Are there any particular models you've been drawn to that folks can advise on?