It seems to me that the question of adding an accent or not is part & parcel of our being involved with a (mostly) oral/aural tradition. It's sort of an inclination to sing a song the way I've learned it, & I've learned it by hearing someone else sing it.I'm not so likely to put an accent on words I've learned from paper. And if I've heard many singers perform a song --for example, I've heard "No Man's Land" performed by singers from June Tabor to Ed Trickett to Charlie King to Priscilla Herdman--I'm less likely to use any one singer's style or accent because it's all mixed up & composted together.
While we're at it, we might talk about "accents" for the accompaniment--Is tuning your guitar to DADGAD trying to play with an Irish accent? ;-> (Of course if you've had enough of those Irish transfusions--another pint anyone--some of that may seep into your throat & finger muscles, don'cha think so?)
--Tom