How does Sam feel about Alice, given their lore ties? Is he indifferent? Neutral? Does he enjoy her at all? Etc.

Oo, good question!

To me, a base level of indifference is integral to Sam's ability to complete his work. After all, if he were too emotionally invested, how could he enact the experiments? Speak of her like a subject rather than a person?

However, I think he, too, sees the parallels between her to Demi and him to Orpheus. It'd be lost on the untrained eye, but every so often, perhaps a particularly hard day, he'll give away a slight frown and furrow of his brows. Perhaps allow her to rest her head beneath his chest between split-second transfers from laboratory to Vilhelm. Or, when he's truly losing it, snapping at his colleague, demanding they unhand her or treat her with more respect. Perhaps he would hallucinate her as Demi.

Dipping more into theory territory:

If he did assist in Alice's escape, then perhaps the Sam Demi once knew overpowered the forced indifference mandatory for the manor's inner-workings. And, if this reached Vilhelm's ears, it would bring ruin to everything he worked for. To Demi. Would it be a sacrifice worth taking?