I know there is a config to remove the sign editing. I have removed it myself just making you aware of bad interactions.

If you have MoarSigns installed you can edit those signs. That's fine and dandy but the formating data on the sign is lost when the vanilla edit GUI is closed. Along with this it also screws up the tool for moving, copying and editing of signs. I advised MoarSigns put in a warning if quark is installed as it could be overlooked quite easy and causes a lot of frustration. Again this isn't telling you to do anything or nagging you to fix it. Just giving you a heads up that there could be more potential issues with signs on other mods along with letting others know (if they search the issues first).