Use @supports with a proxy feature/value for features you can’t test for (@starting-style)

You can t use @supports to feature test for @starting-style. But what we can do, is use another, different property value pair, that is a good proxy for the level of support we need. In this case, I know that @starting-style came out in Safari 17.5, and at the same time, text-wrap-style was introduced in Safari [ ]