I tried to use the predictive stroke on the desktop version of sketchbook and found it pretty useless to be honest.
Looks cool in promo videos, but doesn’t offer much value.
If you are sketching loosely by hand you usually want that “handsketched” look. Perfectly straight lines and ellipses totally destroy that.
If you want to render something out very precisely predictive stroke just isn’t accurate enough and changes your original lines quite a lot. It is wicked hard to place that perfect line and ellipse in the EXACT location you want and you end up with a lot of undo and then trying it again. In the end I found the ellipse ruler just the more controlled, precise and ultimately faster option.
I would be happy to hear of someone who found it useful. Maybe he or she can share their use of predictive stroke here and it turns out I was just doing it wrong!