This is probably the best use case here:
I loved this level. (side note: best FPS campaign I've ever played I think, I liked it much more than Doom) And it does exactly instant loading no down time and it's based on user interaction.
It runs on a paltry XBO and PS4.
Infact the whole titanfall series is sort of based on this. Which funnily was largely overlooked by the SSD discussion.
So this is why, I know, that if there is a will, there is a way. Both ssds drives will be 50x faster easily than the ones spinning on this gen, but PS5 is only 2x faster than XSX. There are likely limitations caused by the slow hard drive, but I don't think the sony SSD is going to unlock things that much more than what we have on XSX. Just my 2 cents.