Too many NPC persona's listed in Chat for DM to choose from

I've been putting character sheets in roll20.net journal for every monster in the adventure I'm running. The stat block is placed in the DM only notes. When the players make a knowledge check about the monster, I make the character sheet viewable to all character and copy information they get from the knowledge check to the Player view-able notes. I archive any monsters I'm not using for that encounter. I'm playing Pathfinder and my goal is to keep as much of what the character's don't know out of the hands of the players. In the chat, I, as the DM, can select an NPC as my chat name. Problem is every character, no matter if in the archive or not, is in that list. I would suggest taking archived character sheets off the chat option for the DM. They can un-archive the NPC while it's in an encounter. For this adventure alone I'm already at 19 NPC's.

I am in favor of this idea too, though I wonder how hard it would be to put a check box in the character sheets for the NPC's that allows you to select whether or not that NPC appears on your list of personas. Probably not a hot topic for the devs to accomplish, but certainly a nice touch for the GM with a wide variety of NPC's.