Can I use sugar as a pie weight when blind baking at 425F?
Unfortunately sugar decomposes at 367F/186C, so I don't think using it at 425F is a good plan.

That said, I think that lower-temperature blind baking will work on pretty much any pie crust recipe. I've used it on both the Stella Parks recipe you mentioned, and Kenji's easy pie dough and it worked fine.

The benefits of using sugar and of blind baking at a lower temperature are described in yet another article on Serious Eats. The lower temperature reduces the puffing and deforming, and the sugar is just easy and effective. None of it is associated with any specific pie crust recipe, so again, should be fine on the Cook's Illustrated recipe.

Of course, you can also always just pick your favorite plain crust recipe and use it on every pie you ever make that calls for a plain crust, even if it includes its own unique variation, and then you'll know exactly how to deal with blind baking it (with sugar).