Finally got this card and adapter fairly recently. AirDrop works out of the box in High Sierra (iOS to macOS, and macOS to iOS). Handoff, Universal clipboard, iPhone cellular calls on Mac, Instant Hotspot, all work as well. I have not needed to use the Continuity Activation tool.
Been having some issues like random disconnects in Windows, but those seemed to have died down a bit.
edit- nvm these still happen - very frustrating and not sure why it happens
They do appear to be random
I've been having network issues, so I don't know if this card is to blame, if it's Hackintoshing, or something else.
edit2- The Windows driver for this thing is ****. In macOS, unable to connect to a WiFi network after sleep to wake. I'm afraid I can't recommend this card. I'll be switching back to my reliable WDN4800 soon.
edit3- After reinstalling the OSes, reseating the card, and using the latest driver from Boot Camp Support 5.1.5769, the issues seem to have gone away. I can't tell if the issues have been from it not being properly seated, if it now works because of a more recent driver, or if it was something to do with OS configuration.