Nialler: "Additionally, if boarding cards can feature a seat number they can equally indicate the nearest emergency exit to that seat (given that it's available in the event)."
Have you considered that the reason airlines do NOT tell you where the nearest exit to your seat is, is to protect you, in case of the unfortunate possibility where THAT exit becomes unavailable due to, for instance. a fire on its outside to name one of a not limited amount of options?
If you tell SLF to get out of THAT exit, they WILL, and risk their lives versus getting out of a SERVICEABLE exit elsewhere, which could save their life.