First of all, I'm not using MPS with my Nature2. Zodiac has instructions for using only dichlor with Nature2.
So, my interpretation is that this is to expect, especially accounting the heavy usage and thus the chlorine usage/consumption. I just have to keep track of the PH and alkalinity and adjust them both accordingly. If I raise my TA first, would that also raise my PH? Or would I need to use both PH and Alk. increasers?