Ubuntu have a full TB3 suport with Dell "sputnik" devices like Dell XPS 13 or 15 that have TB3 connector. Maybe you can look their kernel sources:
https://launchpad.net/ubuntu/+source/linux-oem-osp1/5.0.0-1052.57
Not sure if they are using proprietary drivers.
Look this:
https://github.com/jonasmalacofilho/liquidctl
Plus this:
https://github.com/jonasmalacofilho/liquidctl/blob/master/docs/nzxt-smart-device-v1-guide.md
Maybe someone can make a plugin to integrate natively to Unraid with NZXT V3 controller.