I'm trying to make my own repack collection but i'm having a hard time finding the perfect general parameter that suites all kinds of data or maybe two.
I'm seeing alot of repacks floating over the internet and for educational purpose i've checked some of them but sadly all of the arc files are password protected so it's impossible to know the compression method used.
What i'm sure is about the repacks i've checked that they are compressed in one command not arc>pcf>srep>arc.
The most interesting repacks i've seen made by RG and AGB because they are always have the smallest size with the same data.

Would you please help me in this issue please? or it would be awesome if you know the used parameters by those repacking groups.

For instance i'm using this parameter for arc+srep+lzma: -msrep+lzma:a1:mfbt4:d256m:fb128:mc1000:lc8

Any suggestion for improving the compression ratio is very welcomed.

Thank you and sorry for the long post.