But even if you disagree with this, it is still clear that it is going to become a problem at 3x or 4x or so.
I don’t know enough about the inner workings to know whether this is true or not.
I obviously trust your judgment on these types of things (more than mine) but I am also not 100% convinced that it wouldn’t work to have the shared memory file grow to several hundred GB (or more), and still only require 16-32 GB of RAM.
it may work, but it will just be extremely slow, not only full replay but even syncing a few days of blockchain after downtime. This is already the case at 30-something GB state with 16 GB RAM and 2x NVMe RAID0. I'm not really sure what they are thinking when they claim 8 GB is still usable. It certainly isn't for me, I was very seriously considering dumping the 16 GB, but i haven't yet.