Why careful is not a workable instruction
Telling someone to be careful around equipment relies on them knowing what matters, which requires familiarity with a production environment that most cleaners will not have. Gaffer tape on a floor marking a position looks like debris. A cable run looks like something to tidy. A carefully placed acoustic panel looks like it has been left in the way. All of these are reasonable readings and all of them cause problems.
An exclusion removes the judgement. The area inside the marked boundary is not entered, and the responsibility for cleaning it sits with the client's own team who understand what is where. That is not a lesser service. It is the arrangement that produces the fewest incidents, and studios generally recognise it immediately as the sensible position once it is offered.
