Unfortunately, I hadn't had a chance to follow up on the header installation. I filed a bug to make sure we don't forget.
As to the Linux NVIDIA TLS library: we ship two libnvidia-tls libraries on Linux, a new-style ELF one and a classic one. Which one (or which set) is installed depends on the host - the tls_test* binaries determine this (they've been used by `nvidia-installer` on Linux for a long time now).
Traditionally, we only shipped the classic NVIDIA TLS library on FreeBSD, which no longer works with modern FreeBSD/linux_base combinations. We now also ship both libraries on FreeBSD and use the same test program to determine which to install.