I think it's important to remember that just because you found an online calculator that does something, don't assume it's accurate.
There isn't "missing data" that needs to be inserted into beersmith. There are just so many variables that it's easier to do a test run and input your specific readings yourself. For instance a low BTU burner in Houston Texas is going to boil of a significant amount less than a high BTU burner in Phoenix Arizona due to humidity. A dip tube 1/4 inch lower in a wide boil kettle will leave a significant amount of wort compared to a skinnier tall boil kettle with the dip ripe 1/4 inch higher. There are so many different variables that, in my opinion, input of your actual readings is the best way to do it. There is the simple way of doing things and the right way of doing things. Sometimes they are the same, other times they are not. My point is beer smith is used to let us be as accurate as we possibly can with our readings so we can maintain as much consistency as possible at the home brewing level. There are simpler ways and things that can be "close enough" for people to be happy with. But in time most brewers want to be as accurate as possible.
