The thing is, I have a 2 TB SSD plugged in (a replacement for the replacement that had decided to permanently go out to lunch well before this had even become an issue) so I’d expect full SATA-3 performance.

The question still remains: Is the PS4 OS actually allocating swap space or not, and if yes, how much, and if not, could this problem be worked around by adding a swap handler to the game itself?