UltraARC for Inno Setup (Conversion Tool)

[Masquerade]

I think I'm doing something wrong here.

I've used UltraARC now a few times for my compression needs, but I can never seen to get decent compression from anything, I can only really get 300mb or so compression over the original folder size.

Here's the UltraARC log:

Pastebin

I am compressing LEGO Indiana Jones here (which is mainly large .DAT files, with a plethora of small .OGG files since the audio is external to the .DAT files)

Can anyone see what I'm doing wrong? I am using XTool (zlib) + SREP + LOLZ + ZSTD. I don't know how necessary precomp is as well as I'm not too sure if ZSTD is needed on top of LOLZ.

If anyone cna find out how to gain much better compression, I'm all ears