I foresee more edits of this shoot in my immediate future.
Hey when you said Sans doesn't know Flowey, isn't that disproven because Sans remembers timelines? Or at least he can spot anomalies. Since Flowey says (I can't for the life of me remember when), "I've befriended everyone, I've killed everyone. Eventually they all became predicable" so Sans would've met Flowey back when he still had the power to reset and reload.