[Is it possible to keyframe edge points on Mistika?]

I often see the footages where subjects stay on different stitching borderlines at different times. So, I have to adjust edge points, but I wish I can keyframe edge points so that subjects staying on stitching borderlines can be perfectly stitched.

It seems like there's no way to keyframe edge points on Mistika at this point. Any solution for this?

[What causes black hole (black circle) in the top and bottom of a video?]

My questions is simply as the title. Sometimes I see them in a video, and sometimes I don't.

What causes black hole in a video?

My guess is that black hole is made because there's no repetitive pattern on the top and bottom. I'm not sure though.

Please, share your expertise if you know why. Thank you!