Interesting stuff for sure. But I'm not confident we can draw firm conclusions. Take a look at Figure 4 in the first paper. Now focus on the gh burst vs. estradiol for men only ... I don't see a relationship, at least not a strong one. In the upper graph, the slope of the line again comes from mixing men and women. Paper #2 is about women only.
In sept, I began running ghrp6 100mcg 2x per day. Later I experimented with mod grf1-29 on top of this, as well as later adding 1iu of gh. Meanwhile I continued to do "TRT plus" - blood levels around 1200 on testim - plus 0.5 mg a-dex per day (estradiol has been running arnd 15).
My experience w peptides: pretty good! Nice gains, esp. in sept and early oct. Some left shoulder tendinitis went away too. My igf-1 went from 200 to 400+. Got one reading over 500 which kinda scared me. I haven't sorted the relative contributions of ghrp6 vs grf. My sense is that ghrp6 is the real driver, with an additive effect from grf.
Anyhow, all this happened in a low estrogen situation.
Then added some test-e, got bloated because of extra E, and ironically saw fewer if any gains. Maybe it's just me.