We purposely have these and have them cheap so you both have one for future use and maybe a mates use etc.. so you will do it right to start with.
Use of this tool prevents the inconvenience of accidentally tripping your proportioning valve during the brake bleeding process, if you don't use it in place of the fail switch during bleeding your going to claim the proportioning valve has failed.. or your service person will.
Tool is made of lightweight, durable nylon to protect the threads on your valve from damage due to accidental over tension.