Yes, this is why I mentioned having so many parallel agents and being compute bound. I run on my own laptop and 2 high-end desktop machines all with 64gb RAM. And it still occasionally happens that one OOM kills codex. They also mostly run unattended until I need to switch their accounts because a usage limit has been hit. Each instance usually can keep going when I sleep or do other things.

I only save the last 30% of usage on a single account for most of my other work, and that is almost always enough.

Sounds like you might benefit from running a custom harness then, no? I can't imagine for a task such as that- that codex is the best option.