Better HRT results following SRS? Absolutely!!!! I had SRS about a year and a half ago, and I've experienced SIGNIFICANT breast growth, and SIGNIFICANT changes in the contour of my butt, definitely fuller and rounder.
There were virtually no gains from HRT prior to SRS, and even though breast development has been significant, there still is insufficient development to fill out a bra. There are no guarantees with this, and YMMV. Post-op, some change their HRT protocol, some do not, another factor to consider.
I've also experienced an undesirable gain in weight, with most fat settling in my midsection.