Hi, NLP will work for LR6, which you can still purchase as a standalone. The reason is won’t work for LR5 is that I need access to things in the SDK that weren’t introduced until LR6. For Capture One, the biggest issue is that even though they now have an SDK for plugins, it is extremely restrictive - it doesn’t give me access to the same kind of deep integration that makes Negative Lab Pro work so well on Lightroom. But perhaps that will change over time!
-Nate