Dr.PulmRoch said:

One practical note: write down what you did and when, before you need it.

Agreed on the substance. I would put less weight on the timescale, because two months of anything is not enough to distinguish a trend from a wobble.

Dr.PulmRoch said:

One practical note: write down what you did and when, before you need it.

Thank you for spelling out the reasoning rather than just the conclusion. Taking it to my next appointment.

Adding the clinical framing, because it changes how the question reads. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.

andrew_nyc said:

The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either.

Same pattern here, and in the same order. Nothing to add that would improve it.

Reporting back.

Reporting back for the archive rather than for the thread: I did the narrow version of what was suggested, gave it the full interval, and it settled. Posting it because threads without a follow-up are half a thread.