I can get about 20 ~ 40 minutes of my 5-hour limit using Codex 5.4 medium to say write a patch script in typescript for a Firebase + BigQuery app. That's including about 10 minutes of first writing a planning.md doc with 5.2 High.

A couple weeks ago I'd get roughly 2~3 hours. And a month before that I couldn't break the 5-hour limit.