Hi Matthew,

Thanks for making this request. To save a currently propagated Roto Brush span, use the Freeze button in the bottom bar of the Layer panel while Roto Brush & Refine Edge is selected in the View dropdown menu ( see attached image ). This will prevent Roto Brush from re-propagating on project open and when other aspects of the project are modified.

Roto Brush should only re-propagate when there isn't enough RAM to hold its cache or when the footage with Roto Brush applied is modified "upstream" i.e. when a mask or some other footage attribute is modified before the pixels are passed on to the Roto Brush effect. Some of the scenarios you've listed, like closing and re-opening a project or moving the footage to a different comp, should trigger re-propagation unless you've frozen the propagation as mentioned above. The other scenarios shouldn't trigger re-propagation unless the RAM cache has also been cleared.

If possible, please file a separate report about the propagation being re-propagated in the cases where the RAM cache is not being cleared along with a screen recording of the unwanted re-propagation occurring.

Thanks again for making this report,

- John, After Effects Engineering Team