Tell them to set the toe, nothing else is adjustable
This is correct, but by attaching their equipment on all four wheels. They can assure that it tracks correct. That is drives straight when the steering wheel is set to straight. You could unscrew the steering wheel and correct if nessesary but i'd rather let the guy do his job, instead of micromanaging his tasks. They usually know what they are doing.
Also if you have some damages to your car that off-sets a rear wheel. That you were not aware of. This would also show up on his report. This is valuable i think.