Great it works thanks a lot! Maybe one idea: what about a "comparing" tool with all precomp versions? Maybe you can integrate it in your great script
I also had the idea, that the batch finds out the biggest files and do some compressing tests with intense or brute method (to also get GTA5 files compressed). After the test run, there will be a short message saying for example" Precomp 4.2 with intense mode" is the best option.
I think it will be hard to implement automatically, but you could do a big script for all precomp versions and options so that you will be able to test it on one big file which you manually choose. Then you can compare the results and set the best option.
I hope you understand what I mean