Nate has addressed this in another thread: Idea: Make Negative Lab Pro for other programs (Capture One, Affinity, Luminar, Affinity, Lightroom 5, etc)
Long story short: Capture One’s SDK doesn’t support enough features for NLP to be ported.
Which is disappointing to me, too. I don’t even really need LR at all: just something to manage tethering to my Sony camera for shooting negs, and NLP to do the conversion.