Hello gbp,
In the version 2.2.0 there will be an option "save project after each step" for major processing operations.
So if there is a problem during processing operation related to the unexpected Metashape or system termination (crash, shut down, etc) it would be possible to continue the processing almost from the same moment when the problem occurred. That is, after the problem occurred when reopening the project, processing will automatically continue from the previous saved task on which the failure occurred.