0.02 - 3 gpm
You just have to check with a drip bucket or you stock tank that the fertilizer is coming out of your dosatron is what you want.
Mixing fertilizers is fine, don't mix calcium with sulfates or phosphates unless you like calcium sulfate and calcium phosphate sludge that solidifies.
Calcium nitrate and magnesium sulfate different tanks, phosphate is same tank as sulfate. A B system is a tank that keeps these separate then mix in the injector to your irrigation tank/mixing tube.
Mono Potassium Phosphate
These are examples of what usually may go into an A B system for the fertilizer concentrate solutions. Not all the fertilizers are put in, it depends on crop, grower and recipe.
Single stock Solution is simple as well you just dump into one tank and dial in what you need.
Some fertilizers come with instructions even if 2 part system then tell you how concentrated to make it and which dilution ratio to use usually for ppm of N.
It is not really that much work it's just checking to make sure everything is doing what it is supposed to.