Plenty of experience with blowouts on old as shit tires, a thank you. Dry rubber does not help with any thermal and expansion properties like a tire is designed for when it ages that much. Even if there is no visible wear marks, the material is different. You can argue for your cause all you want. I get that, and go for it, keep them as long as you get and get every mile out of them tires. The science is real. Experiences may vary.