To clarify (and the drop in the ocean was an elaboration of the exchange we had earlier where I said there had to be a limit or else we could put one drop of toner in 10 gallons of water and tone to completion instantly ) ...
The reason I use it that way (with MGWT) was just that Drew Wiley in another thread here recommended it at 1/4 strength for MGWT. I followed his process and loved the results. That included using a water bath, toning for no more than 20 seconds and then dumping the print into the water bath with no drain time (which will cause streaking, it's so fast with MGWT.) Done this way it does continue to tone a while in the water, which is one reason to stop before it's where you want it. But it doesn't bloom or boom or whatever (greatly speed up etc.) It just continues a bit then stops, or almost stops as it will tone a bit more during washing. If it isn't enough, back in the toner with it. I modified this on my own, not having Rudman's book or reading of this "works faster when more dilute" thing, because it was hard to control with such short times. If nothing else, sometimes the print will stick or something and it will take a bit to get the tongs on it. Do not try to grab it with your hands, with or without gloves - heat speeds up the toning drastically and your hands, even through gloves, are warm and will leave fingerprints. Don't ask me how I know. So I went to 1/8th strength dilution and that certainly is slower than 1/4 strength. I make no claims (with MGWT, more on this...) about the speed of 1/4 versus full, which may be faster. I don't know. But I do know that 1/8th strength is about half as fast as 1/4 strength so I at least seem to be hitting that diminish effects point.
I just toned an 11x14. A friend, and very good digital photographer, greatly admired one of my toned, mounted 11x14s, so I offered him a copy - he's moving away, and it's a moving away present, in part. Before he left he gave my wife and me his very first darkroom print from the days when he did darkroom. Anyway, I needed to duplicate the earlier print, which I had toned for approximately 45 seconds at 1/4 strength. In 1/8th strength toner I got a pretty good match for it with two minutes of toning, which I find much more controllable.
I did mix full strength toner to try with Arista Private Reserve RC Pearl, aka (most people think anyway) Adox MCP 312. It responded in the weak toner but I didn't like it. It was an odd reddish brown that I didn't care for, and took a lot longer than MGWT. I think anything takes a lot longer than MGWT. I mixed full strength and got a pretty nice chocolate brown with 10 minutes of toning. I can scan that if anyone is interested. It's a cooler brown than you'll get on a warm tone paper like MGWT. The red tone I didn't like I got after several minutes in the very dilute toner. When I mixed it full strength I just put the same print in for another 10 minutes so it's hard to say if it's faster with one or the other. It's different, though.
Here's what my toning looks like on MGWT with 50 seconds in the 1/8th strength toner, for a light toning effect I like very much:
T. Allen Greenfield 1 - MGIVWT+Brown Toner by Roger Cole, on Flickr
Here's the same paper, otherwise same processing, but toned for 40 seconds in 1/4 strength. Considerably more toning than the 50 seconds at 1/8th:
New Orleans Courtyard - Toned by Roger Cole, on Flickr
And another, my now wife then fiance, also 40 seconds at 1/4 strength:
Alicia Park Bench - Toned1 by Roger Cole, on Flickr
Those 40 second results look good for some images but were just too strong for others, and really short times like 20 seconds were just too hard to control. So for this particular paper I like the weak toner.
One thing though - it doesn't last very long after mixing. At these weak strengths it is noticeably weaker the next day, and almost useless a week later. Tkamiya says his full strength toner lasts for a very long time. I did have that full strength toner mixed, but when I got no response at all out of Arista Silver Artist after 10 minutes I mixed a fresh batch - which gave no change at all after another 10 minutes. Now there's a paper that resists sulfide toning. Otherwise I haven't kept full strength toner enough to know.