Codex compaction is really quite good. Smaller context doesn't really harm me.

I had a /goal running last night for 9.5 hours straight while I slept. When I woke up in the morning it was fully on task and focused.

Write up a detailed design doc. Build a decent AGENTS.md, and write up a good prompt or /goal.

Long context can be more of a curse than a benefit sometimes anyways.