That works once or twice. After you consistently get done in half the time, your secret is out, and they just assume you’re doing it again and will be done in half the time. Better to save this for those jobs you think could have complications.
Same for the “sleeve” bunkers I know you don’t keep. After the drafts didn’t work out as calculated a few times, it’s pretty easy to learn each chief’s propensities. The only difficulty is guessing which end they’re being hidden in each voyage.