If I read stuff like that, I wonder what the F they are doing. Agents work overnight? On what? Stuck in some loop, trying to figure out how to solve a bug by trial and error because the agent isn't capable of finding the right solution? Nothing good will come out of that. When the agent clearly isn't capable of solving an issue in a reasonable amount of time, it needs help. Quite often, a hint is enough. That, of course, requires the developer to still understand what the agent is doing. Otherwise, most likely, it will sooner or later do something stupid to "solve" the issue. And later, you need to clean up that mess.
If your prompt is good and the agent is capable of implementing it correctly, it will be done in 10 minutes or less. If not, you still need to step in.