I don't believe there is any explicit wording to say an LLC owner cannot take payroll as a W2 employee but it seems to be heavily implied when you look at the instructions for line 26 (deduction for salaries and wages paid) it states: ".......do not include amounts paid to yourself". So even if an owner paid themselves on W2 they would not be allowed to include the amount in deductible wages and salaries against the LLC which makes it illogical to pay themselves as a W2 employee.
