I would suggest keeping estrogen in the normal range. Its about a balance, not too much but not too little. Of course, if you get too high, you end up with bad sides like gyno but before you reach those sides, you’ll find more water retention and fat gain. I would always use an AI from the start of the cycle. Then if you want to do a mid cycle lab panel, you’ll see if your estrogen is in a good place. For off season, more on the higher side of normal is fine. When working on fat loss, on the lower end of normal.