I think it's the fact that I don't have to actively be aware that I should be ignoring /tells (most of them are RMT), but whenever I do a DF, it's really one of those rare moments that I regain that sense of immersion. So nah, I think I'm fairly content with not having a /tell function active in dungeons (for now). Not to mention, as someone else shared, anyone of mention is in my LS/FC anyway.