Alright so I made the script. Edit it for your game path, change ztool parameters as needed and run it. It need DD command for windows which you can get here:
http://www.chrysocome.net/dd.
Next you need 7zip, specifically 7z.exe and 7z.dll only, and ztool.
Place everything in one folder, including my attached script
scan.zip and you are good to go. This script will show time at the beginning and the end of work(not shown on the pic as I added it later) and it will show original as well as pre-processed size at the end:
scrpt.png
This script is
slower than GFS as I found, probably because inefficient serial piping, but still "ok" and reliable. Unlike GFS, feel free to set up as many threads on ztool as you can to speed it up without reliability cost.
I recommend this for plz4 and plzo since they hang, you can keep using pzlib on GFS(with dynamic streams on) to get more or less same accuracy while being quicker. But if you want to have exact size that you would get using ztool, you can still use this for pzlib as well.
PS: since this doesnt utilize disk fully(like GFS do), you could have say 3 different batch script versions in the folder, one for pzlib, plz4 and plzo respectively and run all 3 of them at once.