Re: "other [variables] are at least as important" being an incorrect assumption...
I can see this being possible for some foods (your salmon steak being a good example, given you include thickness, but you'd need different models for many different types of fish), but really unlikely for others. How onion behaves, for example, is pretty regional and highly dependent on type. For many vegetables water content is highly variable and very important to how it cooks, but I feel like i've got better proxys for what is going on than cooking surface temperature would be....
This isn't targetted at the experienced cook. It's targetted at somebody with limited experience cooking who wants a little more probability at success. My internal geek is fascinated by it, and I'd buy it if I had the spare cash lying around, but my internal cook sees its applicability limited (though perfect salmon every time is tempting; I'm not that great with fish).
It's unfortunate that the generational tradition of teaching cooking really fell apart in the last 40-50 years. My generation was the first who had to completely teach themselves.
Re: "other [variables] are at least as important" being an incorrect assumption...
I can see this being possible for some foods (your salmon steak being a good example, given you include thickness, but you'd need different models for many different types of fish), but really unlikely for others. How onion behaves, for example, is pretty regional and highly dependent on type. For many vegetables water content is highly variable and very important to how it cooks, but I feel like i've got better proxys for what is going on than cooking surface temperature would be....