Please consider implementing xoshiro256** (and/or xoshiro256+)

https://nullprogram.com/blog/2017/09/21/
"xoroshiro128+ fails PractRand very badly. [..] Since this article was published, its authors have supplanted it with xoshiro256**. It has essentially the same performance, but better statistical properties. xoshiro256** is now my preferred PRNG"

See also my https://github.com/JuliaLang/julia/issues/27614#issuecomment-454749117 for others to possibly implement (mostly Google's Randen based on AES, the one I list here would however be my first choice) and updated top comment there.