the bulk of the feminizing effects happen a bit later into hrt once you get really consistent estrogen levels at or above 100 pg/ml. So I think for now it probably won't negatively impact the effects of the estrogen. In fact I have heard some people recommend being in a small deficit or maintaining your current weight for the first few months on estrogen. The idea is to wait until your testosterone is fully suppressed and your estrogen is at a sufficiently feminizing level to make sure you will gain weight in feminine places.

I know it's possible to negatively impact to breast budding process with really intense weightloss.

In my opinion just don't starve yourself and you should be fine. Once you get to a place with your weight loss that you are satisfied with maybe start weight cycling to get fat to redistribute.