Welcome to the Community @raffle
I moved your post into this one about wall ovens. A related and very germane topic is
AFAIK the only 70cm oven on our market is the SMEG 70cm pyrolytic. Choice can confirm, but it has probably not been included because it is an outlier with a small customer base - eg it has a minor market share and Choice budgets dictate they are used wisely.
I have one now 4 1/2 years old. I did not want it but had a 74.5 cm (then called a 75cm) that needed a 75cm cutout, and todays 75cm models are actually 75cm needing a slightly larger cutout. I understand your pain since enlarging the cutout could not happen, and installing proud instead of flush does not suit the eyes. So the SMEG it was. We had 2 stainless bars made to fair in the sides - at first glance it looks like the way it was made and intended. Only on 2nd or 3rd glance are the differences in the stainless brushing evident.
Observations - the enamelling on the oven roof (removable part) reflects where it was hung. There are rough spots that do not seem to impact longevity but suggest basic approaches to firing. SMEG promised a better one but every one they got in was the same +/-. Another irritation is the telescoping frames have vertical wires and the bottoms are not rounded so removing them as required for a cleaning cycle makes scratching the interior too easy.
Operation: More programs than we could figure out what to do with and why anyone would need them. Some of them heat up ridiculously slowly; we use convection, fan forced, or fan grill 95% of the time. We do not bake or slow cook but the programs are there.
The control knob is a hostile design for a while but once one gets used to it (it is essentially a joy stick to navigate menus) it is not so bad. If one is cooking and wants the grill, the program has to be cancelled and the grill program selected. It always wants to heat up after that no matter that it is already at temperature so we cancel-select grill and cook away just fine.
The spacing of the racks is poor. The middle rack is perfect; the bottom one does not have much clearance to the middle limiting what can be cooked with the middle rack in place; the top is very close to the grill element. The previous version to ours had slide racks (not telescoping) that seemed much better spaced. Temperature consistency across the oven is not perfect but isn’t bad. Most things come out better if rotated once every 15-30 minutes. Temperature accuracy is very good as compared to an oven thermometer.
The pyrolytic clean works well but the wire racks, telescoping rack, and roof need to be removed. Maybe the roof doesn’t. Some docs say yes and some no. Writing of docs the descriptive text for the programs is a waste of ink. Back when SMEG had (and might still) have a local showroom including cooking demos and classes. They did a good job of trying to explain it all. I did less well of a job listening and understanding 
Would I buy another? Yes. No choice (no pun). Could a 60cm be installed? Easier than you might think. It would require some easy to do framing to mount it, and some side panels made to fill out the sides.
Anything I missed?
