I would suggest just going with the frequent water change route. Just doing a 10% change weekly, with a good reef salt mix, would eliminate the need for all these supplements. You could possibly need to buffer once in a while, but that's about it. It's near impossible to supplement all these different levels correctly. All these levels are balanced in a salt mix, and this is the most effective, simplest way to maintain them.
Supplementing becomes confusing and expensive, and doesn't work nearly as well as a simple water change.
My tank is heavily stocked with coral and the only things I supplement are Ca
, Mag. ( with a 2-part supplement) and a Ph buffer.
I've tried it both ways and trying to supplement everything, ends up feeling like your always chasing your own tail. It's much easier to just do water changes.