It's shocking that race tracks are still allowed to use leaded gas. Anyone who's using leaded gasoline has a dedicated track only car, so they're not switching between street use and track use. The benefits of leaded gasoline have long sense past and there are suitable replacements that provide the same benefits. Additionally engines that were built for leaded gasoline use that are still in track cars today would have been rebuilt and could have the necessary modifications to not use leaded gasoline.

Farm equipment and certain other off-road equipment might still need leaded gas depending on the situation. This would be typically fairly old equipment at this point, as in 40+ year-old equipment. I certainly wouldn't want to buy any food from a farmer that is still using a leaded gas to power their equipment. That same equipment, if it is not then rebuilt, is likely spewing lots of other dangerous emissions you would not want in your food supply. So I would think that if you still wanted to run let it gasoline for any off-road purpose you should have to justify its use.