Unpopular opinion: I stopped putting my car on jack stands for winter and it's fine
For years I kept my project car on stands in the garage from November to April because everyone said tires would flat spot, then a guy at a shop in Boise told me modern radial tires just don't do that anymore. Six winters later, no flat spots, and my suspension is actually happier sitting on its own weight, so what are you all doing with your stored cars?
What made you trust the guy at the shop over the fifteen years of conventional wisdom before that? A tire guy in Boise could be right, but tires also age out and get hard whether they sit on stands or not, so I'm wondering how you ruled out the rubber just getting stiffer over those six winters. Did you notice any difference in how the car drove the first spring compared to the later ones?