as fitgirl said 4x4 is not good to use for public repacks you can use it for your personnel repacks it require 4X what normal lzma require but also faster ,
one more thing RLD didn't use 4x4:lzma they used 4x4:tor
you don't have to use 4x4 for lzma only
but it will be a good option for a fast storing with a light compression ratio
