IMO, tds is a misunderstood tool that makes people chase non existent problems. 200 tds with ferts in the water is not the same as 200 tds of waste. If you want to use tds, find out what your tank is at after a water change, gh booster, and any ferts you use, and use that as a starting point. TDS will be higher for higher ph/gh water. For example, if your TDS after all the above is 150, then base any water changes off of that as a starting point.
I target my re-mineralized water based on gh. I typically only use the R/O for one tank, my south american tank, and keep around a gh of 7, which leaves me with a stable ph around 7.2. I use around when re-mineralizing water because in my experience there will always be some slight gh/ph variation in the tank. I do use gh booster and ro for my africans and guppies seasonally based on how my well is, but it takes a significant amount to get there.
edited for grammer