Unfortunately I was the only one that ever tested the game before the jam deadline, and it seems the meter is much easier to time on a high refresh rate monitor while playing at high fps. The framerate is unlocked in unity, but the web build will be limited to the framerate that the browser tells it to run at. If I play on my main monitor it's 144 fps and feels reasonable to time, but on my second monitor it's 60 fps and feels noticeably harder to time. If yours (and other people's) are running at 30 fps for whatever reason, then I can definitely see how that would feel really bad to time. I'll probably consider locking my jam games to 60 fps in the future, for a more consistent experience regardless of the hardware/software that runs it.
Thanks for playing, and thanks for the feedback!