Yes, there is a lot to be said for feeling something is better as we can then move on to other things and there are always points we may want to improve.
Ferts is a point that I found not nearly as hard as it sounded at first as it seemed really risky to start dumping stuff into the tank after years years fighting to keep the tank clean. The whole point of fish keeping used to be to tear down the tank and get it totally clean---until we came around to knowing about the nitrogen cycle and all that good bacteria we need to take care of the ammonia.
Seemed just really dumb to vac a tank of every speck and then see folks use DIRT in them?
So now I look at the big three ferts, N, P, and K with a bit of the micros added on another day. So finding that there choices can normally be down to three chemicals to get the big three macros and then a simple one item (cms+b?) to do the micros helped me to cut through a lot of the confusion from all the chemistry. I look it as pretty close to the difference in my cooking versus my wife. She can figure out what each ingredient does and have a far wider range of cooking but for me, I can do a few items, taste it and get near enough for the level of cooking which makes me happy without really knowing what each item does in a cake. Since I never really want to do a cake or anything requiring great skill, I'm happy with not knowing!
So the calculator lets me plug in tank size and what item I might want to use. Most use KNO3 as a way to get some of the potassium (K) and nitrogen (N) and what dosing method I like. I use EI as an estimate and it spits out how much KNO3 to add. It tells me how many PPM but I only look at how much in teaspoons and dip it out of the bag to mix in my cup of water before pouring it in! Some of the micros will make some of the macros settle out if we add them at the same time so I do macros one day and micros the next and just go through the week alternating and if I am gone and miss a day, I ignore the break as my plants are not all that fussy.
I am certain that I am not getting the true high level growth but then I don't bake that cake!!! I'm more a low level, happy to see something good and do a little trimming here, a little algae fight all the time and set by to not worry it too much! As long as I don't tell them how screwed up the tanks are, the visitors are highly impressed, so I just keep my mouth shut on that point.
Most sources can provide a simple big three macro and a micro mix to make it easy to get , until the time when you may want to bake the big cake? I'm more a "ham and eggs" sort and buy the cake if I need it.