Im not sure if there is one yet but id like to put in a request for a sign editor, I have lots of signs placed in various places, it would be nice if I was able to edit them without having to remove and replace, this would also make copy and pasting much easier with signs.
not quite, I want to wield an item or hold a key down and then you "tap" or right click be able to change text of that specific sign. although something like you suggest would be nice. for example: if you tap a sign, it gets line1,2,3,4 and if any other sign matches the lines it gets also replace those within x range?