Nixing these ooc signals makes for so many fun opportunities. With more and more being tied to a sic chip instead of your charname, the options for legit undercover shit are huge and don't need staff involvement or handwaving.
Id like to throw another crazy idea on the fire: an option to have "two names" or "yellow npc names" when you hit stupidly high levels of disguise. For better or worse, people still act differently around npcs. It would be really fun to play around with that expectation. I think it could help disguised players enforce the "I'm a stranger capable of everything" aspect that makes SD so dicy when npcs are puppeted.