Right, but there's a big difference between "Don't estimate until you've done your due diligence" and "Don't estimate". It's perfectly reasonable to say "This

Right, but there's a big difference between "Don't estimate until you've done your due diligence" and "Don't estimate". It's perfectly reasonable to say "This is a big project, it'll take me a week to know where we stand"- there, you've provided an estimate of the scoping task and promised an estimate in the future as well.