Interesting, but lacking much in terms of the criteria I listed. My idea was to see a model that would tell users what to expect from a product (not a DIY LED setup) and, where the user does have control, what to do. This what the EI models do.
For example: You have a tank that is 12" wide and 30" long with a water depth to the substrate of 13" and you want the light to be 5" above the water surface. You put those numbers into the calculator. You want a PAR of 70 at the substrate. You are looking at several different brands and models of LED lights (not DIY emitters). The calculator would ask for PAR and estimated PUR values at important wavelengths (blues and reds) based upon the manufacturers spectral distribution chart. Although the calculator would allow you to choose from many of the more popular brands and have all of those particular specs included, you would still have the option to input PAR, PUR estimates, beam angle, etc., if the brand wasn't in the calculators list. Is it direct lighting or do you have a glass cover that will destroy parts of the blue spectrum. Acrylic is much better, so output be different.
Now you can play with each variable to find optimal values for your situation. You see that the GroBeam 600 is more than enough and might do best at 7" above the water surface. However, some other brands can do almost as well. Yes, you can plow through these calculations without such a calculator, but it could take hours to comparison shop or to find optimal settings for your current light setup. Such a calculator would save that time and make it so much easier, especially for novices, to get it right the first time.
If I had the know-how, I'd do it myself.