I used those tow hooks on my first tractor without any support plates. Even though that bucket was pretty thick by today's standards, it deformed the sheet metal a little. And when I needed to use a chain, I wrapped it around the hook, which was probably too tight of a radius for a chain. Live and learn.
I like Kenny's bolt-on system with the sheet metal sandwiched between support plates, especially with the inside support plate also being a mount for a clevis. Then, as someone else mentioned, make an "adaptor" for when you use straps.