These work well, when you have a completely standard I2C or other serial bus. However, many manufacturers implement something else that is 'like' I2C but not the same. Usually the oscilloscope can't deal with that.
I would like something as simple as using the cursors to indicate the start and end of the serial data, and then have it just show the parallel data from that. Not perfect but it would get you to 90% of what you want.