@drsuefowler, no doubt estrogen is the primary driver for you right now. While there have been studies on progesterone’s effect on osteoblasts years ago, the effects are samll and probably not strong enough to override estrogen’s role. Since it helps you sleep, which is vital for bone health - my opinion is it’s probably best to keep it - double check with your team physicians.

Here are two references on using BTMs as a guide if you want to see the 'maintenance' benchmarks researchers are using:
https://pmc.ncbi.nlm.nih.gov/articles/PMC12064614/
https://academic.oup.com/jbmrplus/article/6/6/e10633/7479596
A move from 9.4 to 9.1 in blood calcium level could be just normal physiological variation. However, getting sufficient calcium through natural food source rather than supplements is always a good idea, especially given the ongoing debates around cvd risk with high-dose supplementation. And im sure you are aware the fact that strontium distorts DXA results. If you're trying to get a clear picture of how well the HRT is maintaining your Tymlos gains, adding strontium might make your future data harder to interpret