Per-file OOM badness

One solution to (I think) all the autosaving issues you raised, which would still handle OOM / crash / reboots is autosaves which are constantly updated and cannot be copied.

This means you can't use the saves to retry, just pick up where you left off. To me that doesn't feel like it would upset any of the games you discuss, any more than just "leaving them paused overnight" (which I used to do on consoles back in my youth).