I am suggesting something along the lines of /cmass. What it would do, is you would type /cmass private on. After that, every chest, sign, door, etc that you punch will become private, until you type /cmass private off. This is good for mass privating, like storage making, etc... If its possible, It would be awesome if you would add it. if its not, then, D: Command: /cmass [lock type] <on/off>
/lwc mode persist I believe that is the command. It does exactly what you just said, lets it stay on so everything you punch is privated. Plus its already in the game.