I've got to tell you, as someone who has been struggling to lose weight as I've gone on in HRT, (I started hormones at 270 lbs, now down to 217,) I have some tips to share about the process.
First of all, fat does not "redistribute." Basically, the way that hormones create more feminine curves is that every year 10% of the body's fat cells die and are replaced. And under the influence of hormones, the new fat cells are more likely to grow in certain gender-specific areas like the breasts and hips. It's this creation of new fat cells that gives you curves. When you lose weight, you are not killing your fat cells, you are merely deflating them. So there is no remedy whatsoever to putting on curves faster through either weight loss or weight gain. The only remedy is time... waiting for the body's slow slow process of death and rebirth to work its magic. (And also exercise. Do butt-building and waist-trimming exercises. Those can definitely help.)
Secondly, once you're on T-blockers and estrogen, losing weight will become a bit more difficult. As the body's muscle mass decreases, losing weight becomes more difficult because your metabolism slows down. Pre-HRT, I lost like 50 lbs over the course of a summer (paleo diet,) while barely even trying. I cheated a LOT and still lost weight. But now that I've been basically eating the same diet that I did to lose that weight as a guy, cheating the exact same amount, it's taken me three months just to lose 18 lbs. I have to stick to the diet twice as rigorously to lose half the amount of weight.
Thirdly, do NOT go off the diet and go on a weight-gain diet once you're on HRT, assuming that all the fat will now go into female areas. It won't. When you gain weight, it distributes the weight evenly among the body's already-existing fat cells. And therefore, you'll basically just be putting it right back where you lost it. The only remedy to getting curves is time. Just letting the body do its thing, create the new fat cells where it needs to create them over the course of months and years. I did try going on a weight-gaining feminization diet, and unfortunately all of the fat just went right back to my stomach.
Fourthly, go on a paleo diet. Trust me, you'll be grateful. You'll feel better, you'll lose a ton of weight, and your body and mind will become VERY healthy.
Again... just have patience, and it will work out. I recommend losing the weight first, because it will be easier plus then you'll have less residual male fat to fight against when the new female fat starts coming in.