Doc just connected with me and it turns out it's all good news. My echo showed that I've had an excellent response to the medication (which I already knew), to the point that the abnormal gradients of pressure in my heart are now virtually non-existent (wow!). He said this necessitates a dose reduction to ensure they don't over-do it, and there may be further adjustments after each future echo.

So I guess this is just how they determine the optimal dose for me. I'm going to stop worrying now and and go back to basking in my new found health.