Why do you think you need to know the overall average including the regroups? If you need to know how long the ride takes, just look at the clock, it doesn't matter what the "speed is".
Of course. But on Sunday, I forgot to note the time when we finished. An extra manual timer would be nice to have, but my computer doesn't have one.
My old bike has a mid-1980's Vetta computer, and you have to manually turn the timer on/off if you want to know average speed. Which I would usually forget to turn on. Or turn off. It's always something.