I have been taking Dapagliflovin (or Forxiga) for almost 3 months now. From a side effects perspective, I have had thrush for about half of that time (on and off). So that's not great. But I have learned to pronounce the name of the drug rather than the brand name, which I'm considering as a achievement!
I do get the chemistry of it. It is intended to help with weight loss since you're excreting sugar/glucose (and hence, calories) that would otherwise be absorbed and stored. I've been trying very hard not to rely on it to make up for a bad diet, but that has been a long term problem. I'm sure if I could sort out the diet, in time the meds wouldn't be needed at all. But I'll continue to work on that.
I wouldn't get too caught up in the figures quoted in terms of grams excreted - you'll not pee out more than you take in!! The idea behind the drug is to stop the glucose being absorbed into the blood and thus keeping your BG level more sensible. Obviously, it will have its limits - if you're taking in 00s of grams of carbs in a day, you're still going to get the blood sugar spikes and physical/emotional effects of that.
But getting into a mode of low carb should bring real benefits in conjunction with Forxiga - at least, that's what I'm taking from it.