That is something I would love to see as well. It would be nice to have a setting for it to be used on the player speaking with the quest NPC too. So, if you set quest::gmcommand("#traindisc 70"), it would be as if the player had access to that command and used it on themselves to train all of their disciplines. Sure, you can just give the players access to that command, but then they have to be made aware of it. With this option, you could have a discipline trainer that works almost exactly like a spell trainer.
Another use for this would be quest::gmcommand("#guild create $name $text"), or something like that so that NPCs could create guilds for players without giving them access to the entire #guild command. It would just set the person speaking to the NPC as the guild leader, and set whatever text they give as their guild name, if that is possible hehe. I realize that there is a command to have NPCs set players to a certain guild, but I don't think it allows them to make their own names.
A big reason I would like it, is so NPCs could reset zones as a work-around for the player ghosts issue. I posted more details about that
here.