On this particular song, I am producing it, even though my engineer is also a producer by trade and is helping me with the project with not only engineering/mixing but also lends producer type skills. He struggles to choose on this one, as well. But, it's up to me.
I can't see suddenly bringing cello in far deep into the song. That would sound odd to me. Like, where did the cello suddenly come from! As for it being a distraction, it is not to my ear. I love it. But, that's just me. To me, it's a matter of... this lyric is all about "me alone," so, we could say that prosody could be enhanced by it being just that (no cello). Although, if we want to get technical, that would mean it would need to be acapella, no guitar, lol.
I like it as guitar/vocal only but love the cello with it, too.
Beats me, looking for opinions to see if I can find a consensus.