Tens of thousands of cars sold with space savers, can’t be wrong? If I was asked to supply a spare wheel(Kia parts manager) it was cheaper to get full size rather than the SS, but they don’t fit in the well in the boot. SS wheels are good till you can get a replacement tyre or a repair, I once ran for about a week until my tyre came into stock, restricted to 50mph but most tyres would be available same/next day.