This proverb seems to state that remaining quiet helps to fix things quicker. Perhaps it is suggesting that less distractions lead to faster repairs. But is this really true in every case? For instance, some people like to shout at their computer while they're fixing it, even though their neighbours bang on the wall and threaten to call the police again. Fortunately, Science and Googles have chartified certain facts relating to this, as seen below, in a chart.
Records of amount said (represented by the blue line) have only been kept since the early 1800s, as before then everyone spoke all funny, all like yea, and verily, and so forth.
As can be seen, the amount said fluctuated greatly until around 1940, the time of www.2, also known as the Great War v2.0
Turning our attention to repair speeds (represented by the red line) we can see that they were very slow until around 1850, then there was suddenly a big rush to repair stuff. Probably everything needed fixing at once, because it hadn't been taken care of earlier.
From 1880 to 1910 there was another period of non-repair, because they'd fixed everything up pretty well. The small mend-intensive blip seen around the 1920s was likely due to Jazz Music, which wore out instruments more quickly than the traditional Classical Rock.
During the Great War v2.0 everything needed to be fixed much more quickly because it kept getting blown up. At the same time, much less was said, at least in part because of the risk of loose lips sinking ships, plus I saw this movie where they had to be quiet in a submarine in case a torpedo heard them.
In the 1960s more was said because people loosened up man, and no-one was in a hurry to mend stuff, because of Free Love, and Drugs.
Then with the discovery of Technology in the 1970s, things started to get repaired more quickly, and at the same time the amount said went down, because everyone was typing and texting, and no-one talked to each other much any more. Sad internet face :(
In conclusion then: well it seems that less is said now and stuff gets mended pretty quickly, whereas in the old days everyone was talking at once and nothing got fixed at all, so I guess it's a trade-off. Perhaps the proverb should be, "Least said soonest mended, but that means people don't really talk to each other any more. Is that really what you want? I guess it's a trade-off". Sad internet face :(