Have you tried it on the front . . . . or the back? The car really doesn't like any tire which isn't very close in overall circumference to the OEM tires and the front and back tires are very different
When I bought my Miata 22 years ago, the 'compact' spare took up an unbelievable chunk of the tiny trunk, so the first thing I did was take it out and put it on a shelf in the garage - It's still there and I've driven that car cross country (without the spare, but carrying a tire plug kit and a compressor) a couple times. With the iMiEV, I'm never that far from home. If I ever did have a flat, I'd call the wife to bring me a spare (the one off the Miata
it fits the iMiEV too) *if* the supplied patch kit and compressor couldn't get me back on the road
But - I understand carrying a spare gives some folks peace of mind, so whatever floats your boat!