will only need to do that for next gen /patched gamea which I'm assuming you meant.
Yeah, I might want to rethink things a bit.
My initial approach was anything I frequently play but won't be patched for nextgen I'd want on the fastest device regardless. So that means the internal 1TB will be filled upto 75% (room left for future game updates or new small titles) and then I'll be juggling things off of it as needed when new games release.
But if prior-gen games show no difference between NVME and external SSD then no need to move them off their current external drives. Certainly would make things easier than doing the juggling up front and so frequently.