Both. There really shouldn't be a debate about this, as I am fond of telling my guitar students, because technique should not get in the way of the efficient performance of the song, tune, or improvisation. If both techniques are possible for the player to execute, then use them where either would be appropriate. My only caution is to avoid any technique which has a damaging physical affect, which shouldn't be a problem with these. Use what is comfortable for you, or what best serves the song or tune.

It is interesting to hear our preferences here. Experienced folkies will influence folkies to come.

Peace, Mooh.