>So I wonder if there are some areas in which this document is lacking or which aren't holding up as well? Ring oscillators have been embedded into Intel/AMD C

>So I wonder if there are some areas in which this document is lacking or which aren't holding up as well? Ring oscillators have been embedded into Intel/AMD CPUs, and they're accessible via RDRAND/RDSEED. Blum-Blum-Shub has been phased out, these days you see AES-based CSRPNGs and Linux uses ChaCha20. The RNG in Linux has been overhauled at least once and so the /dev/random section is outdated. Interestingly the key size recommendations were at around 90 bit range already 20 years ago, and they haven't changed that much. That's still quite close to the password minimum recommendation. Makes you wonder whether it should be closer to the 103 bits now. Triple DES has been deprecated. All in all, the guidance has changed. These days you should not be concerning yourself with any userland CSPRNG, just use the OS syscalls like GETRANDOM. Nothing you do above a kernel module RNG will make it more secure.