> It makes less sense in an era when tenure is better measured in months than years.
If a person's tenure in companies is measured in months then they're signalling they're a C by your logic, or is at least raising a red flag to whoever's hiring. I may be showing my age but that sounds wild to me if that's the norm now.
Your best result is not even an order of magnitude faster, while this repo is claiming on average almost 2 orders of magnitude faster. Extraordinary claims require extraordinary evidence sort of thing.
I'm not getting it. OP said they are wary of letting the agent make choices for them, and outsourcing those choices lessens their understanding of them. They could interrogate the agent on why those choices were made until they have sufficient understanding, and they can also change the solution if they want to.