Watchface diagnostics shows 0 on Mac

Here's what I see with one of my watch faces in low power mode

so right now, onPartialUpdate is taking 9.404 ms  That value might not change much except on analog watch faces where the clip region changes

In low power mode it shows 18 18 0 0 and the values don't change, so the answer is i don't know, the tool doesn't do what my intuition tells me it should do.

The memory tool crashes in 4.1.0 beta1 btw.

Make sure you are in low power mode when looking at this. Settings>low power in the sim.  Watch faces start in high power mode, and you may need to toggle low power off and on to make sure you are in low power mode  You also won't see anything with AMOLED devices or if you're not using onPartialUpdate().