Just wondering what peoples experiences of using Optical Flow slow motion in Motion were?

I've tried it a few times. It was made out to be the ultimate solution for slow motion. But, just as I have found with other software solutions such as Retimer, anything below 50% speed and all sorts of strange distortions start to happen.

Is there anything that can be adjusted to stop these weird picture warpings from happening?

50% is a good speed. Especially if combined with a camera capable of overcranking. But would be nice to know how to get better results with Optical Flow when starting with normal speed footage.

And what happens if you slow a clip down to 50%, export it, reimport it into Motion (as a new clip) and slow it down again to 50%? Does that make any difference?