I just had a pan shot that cut in to a cu in the middle. I slowed the clip down to 71% and applied optical flow. All was very smooth. But at the cut point, optical flow got confused and morphed the two sides of the cut together very nicely over a few frames. So I slid the whole thing down to 10% and now the cut point is a nice slow kinda sorta morph. Nifty. Wouldn't have happened if I hadn't been working with a stack reel with a cut already in it.