If anyone wants to learn (as opposed to arguing), the papers on Netflix's TLS offloading work are a fun read.

And say what you will, something like 20% of all internet traffic has a FreeBSD endpoint. And doing 400Gb/s of encrypted streaming from one box is quite an accomplishment.

I would argue the reason someone like Netflix or any of the other large orgs using FreeBSD come there is for the simplicity/cohesiveness. If you're looking to do something like in-kernel TLS or something, way easier on something smaller, documented, and with an OS devel team that will likely incorporate your work in future releases.