I’ve ran it in my mixed reef with good success. It limits my need for water changes. I do notice over time my calcium tends to run high and mag low, requiring water changes / dosing to fix.
I have been using this exclusively for 2.5
Years and have no concern for measuring calcium or magnesium because it keeps thing nicely in balance + the trace elements. Simplicity has been a win for me. I don’t know if there is an upper limit to where this fails if there is too much biomass but I have hit that yet and I have a lot of coral doing well now.