It’s more of for working with XML workflow and cameras that don’t embed reel names correctly (5d the biggest offender).
In Resolve, an XML clip that comes in without a reel name is unstable, subject to auto re-conforming if I add new footage in. Not to mention, if it doesn’t conform, I can’t even tell what the clip is supposed to be if I navigate to it in the timeline.
All I’m really talking about is being able to chose whether I see the “reel” field or the “filename” field of my XML in the “Conform EDL” box.