I think some of the estrogen-reducing supplements are questionable. I3C or DIM (which are derived from crucifers) are shown to reduce energy production (they interfere with the synthesis of ATP.) It would be nearly impossible to eat enough crucifers to get the amount of I3C or DIM in a single supplement. And the supplement is a fairly recent addition to the marketplace. So without a lot of evidence to back up the safety of the supplement, I’d personally skip it. Also, the claims that DIM reduces estrogen are based on a single study that showed that DIM increased the estrogen metabolites in urine of postmenopausal women in the study.
Calcium glucarate seems possibly safer, though it’s hard to tell. The evidence for efficacy with calcium glucarate is ever-so-slightly better, but not by much.
All in all, I’d probably skip both. I’d go the route of increasing dietary glucaric acid (the glucarate in calcium glucarate) from oranges and potatoes. Glucaric acid is more directly involved in estrogen metabolism in the liver than is DIM. And, the food sources for glucaric acid are otherwise enjoyable/tasty and benign whereas DIM is from crucifers, which aren’t thyroid friendly.
Just my two cents.