The way I try to look at it is, what to dose and how much would be dependent on test results. Values will be higher in fresh made water then the tank, typically. So what you add to the tank will cause a swing from any variable. A swing that is too high above "norm", or a swing that brings parameters to a more ideal range.
Determining what, and how much is consumed on avg. with your tank through testing should create a avg. you can create your own dosage frequency, and amount for the specifics based on that, but that just creates the foundation to build a dosing regiment.
I think dosing after water changes is a waste of time, or counter productive til you have your history of avg's. that help determine when to. Dosing after water changes would be solely for supplementing the new water, and dose accordingly as the values drop for specific parameters. Make sense? I usually don't talk chemistry.
Without a active monitoring system in place it can be tedious to chase all the time.