Fedor definitely pauses, at least on any somewhat difficult shot. I didn’t watch the whole match but I skipped around a bit and that’s what I saw.
So... To characterize a player's use of a pause at the end of the backstroke, we need to say:
- how long the cue stick is completely motionless -- instantaneous, a tenth of a second, three seconds (I'm looking at you, Melling)
- what is the spread of pause times -- always the same, a little variation, from zero to a second, ...
- what shots tend to have more pause -- difficult shot, difficult position, power stroke, ...
- (some other stuff?)
From watching Allison Fisher, I think her pause is from half a second to a second and always close to the same, because it is connected to her eye motion pattern.
I tried to do the characterization a little for a couple of the videos linked above. It was very hard to actually measure the time. YouTube is 1/30th of a second per frame, but sometimes a frame is skipped and sometimes a frame is repeated in the same video, I guess because of the input frame rate.
Also, due to the quality of the video, it can be very, very hard to see if the cue stick is actually stopped, or is just near the "peak" of the swing. Some of the pauses were down at 3 frames or so, which is a tenth of a second, and it's not clear that the stick is really stopped.
You need a good camera angle to get a good measurement. Face-on is nearly worthless; side view and a closeup of the player is best.