I'm skeptical that SPO will be allowed for commercial airliners in our lifetimes. Pilot workloads are fairly low during most routine flights. But when an emergency occurs then the workload suddenly gets extremely high, to the extent that even two pilots are sometimes overwhelmed. This isn't a problem that current automation technology can solve. There are an infinite number of possible emergency scenarios and engineers can't possibly code for and test every one.
Cargo flights over oceans and (mostly) unpopulated areas might be a valid use case for SPO. Cargo pilots have always been considered somewhat expendable.
I watched video about incident where plane was really lucky that there was a pilot riding along in the jump seat when engine went out. The pilots were wrestling the plane and the extra guy was able to debug the real problem. Maybe it was figuring out which engine was on fire and shutting it off.
Cargo flights over oceans and (mostly) unpopulated areas might be a valid use case for SPO. Cargo pilots have always been considered somewhat expendable.