So is the breakthrough just the pre-cooler, or the pre-cooler together with the scimitar engine? It sounds like the innovation is the helium pre-cooler, but ev

So is the breakthrough just the pre-cooler, or the pre-cooler together with the scimitar engine? It sounds like the innovation is the helium pre-cooler, but even at that it's hard for me to understand whether their advancements are in working with liquid helium for a coolant or in the airflow cooling (both)? I don't do anything remotely like this in my day job.