Mooshimeter samples at 4KHz (actually you could go for 8khz, but it is not stable and might produce erros), so it can’t see what happens on that bus. Sounds like a job for an oscilloscope.
Normal multimeter stuff is measurable and you can get graphs with a bit faster rate than you could read on a multimeter display, but basically theres technical limit at ~30Hz. And that rate depends on your sampling settings, so its more like ~3Hz for normal AC RMS measurements.
Normal multimeters however can’t do two things, where mooshimeter shine.. 2 channels simultaneously and logging. It’s mostly just the same measurements as with multimeter, but with ability to graph them quite easily.
Wannabe-oscilloscope-demos are from burst-mode, where mooshimeter about randomly starts to sample at 4 or 8KHz, sends that buffer to your phone and starts sampling again. No triggering or anything like that, just shooting blind and hoping to catch what you hoped for. So basically for mains voltages at 50/60Hz, with great imagination, you could act that you are playing with an oscilloscope.