Just a question here.
When I'm roto brushing (by the way roto brush is working again after latest build :)) I can press spacebar and just see the roto move forward. It's not realtime but at least 5-10 frames per second - amazing. Then when I'm finished and press Freeze, the freezing takes a good 10-20 seconds per frame! Why???
Good observation. When you propagate frames, AE is using an ephemeral cache (memory). Freeze is writing the propagated frames to disk cache. We're planning to improve this behavior is a future version of RB (i.e., "Use segmentation cache when freezing frames").
Oh good 🙂