> Spend most time prioritizing/discussing what to do.

you should probably be doing this discussion work along with Fable 5. It will give good feedback if you're working on the correct things.

> Come up with QA plan and have Codex Computer Use execute on it

QA plan should be part of the above "design + plan", not after it. The implementer needs to be able to fully test before publishing a PR. This is true whether humans or agents are writing the code.

> Manually spot check the final result (usually a sizable diff, thousands of lines, complete feature E2E, etc)

unfortunately this is not really scalable with amount of code agents can produce, so you need independent (fresh context) agent reviewers to help. Ideally they only escalate to a human when really stuck.

> I probably spend like $80 a day at least

at a small startup you should be on the $200/month plan(s).