Using this purely as an admin tool and dont want players to know its there, disatance to 0 is probably the solution but it would be good if either there was an option to turn it off or if players dont have the perm to use it dont warn them at all.

I checked the code set it -1 and it should avoid the message.  Zero might work unless they walk precisely over it, thus the suggestion of -1. I tested it and it works.