[KaktoR]

I made a custom method using DSG. I just tested with my own installer and it works, but not tested with CIU.

However you need to add cmd commands to Setup.ini if you're using CIU.

[CMDCommands]
setlocal EnableDelayedExpansion EnableExtensions
cd /D "{app}\basis_out"
"{app}\7z.exe" a -mx5 -tzip -poKoo$]bnGTKJLMNBA9A "{app}\basis.pak" "*"
cd /D "{app}\patch_002_out"
"{app}\7z.exe" a -mx5 -tzip -poKoo$]bnGTKJLMNBA9A "{app}\patch_002.pak" "*"
cd /D "{app}\patch_003_out"
"{app}\7z.exe" a -mx5 -tzip -poKoo$]bnGTKJLMNBA9A "{app}\patch_003.pak" "*"
cd /D "{app}\patch_004_out"
"{app}\7z.exe" a -mx5 -tzip -poKoo$]bnGTKJLMNBA9A "{app}\patch_004.pak" "*"
cd /D "{app}\patch_005_out"
"{app}\7z.exe" a -mx5 -tzip -poKoo$]bnGTKJLMNBA9A "{app}\patch_005.pak" "*"
cd /D "{app}"
del /F /S /Q "{app}\7z.dll"
del /S /F /Q "{app}\7z.exe"
rd /s /q "{app}\basis_out"
rd /s /q "{app}\patch_002_out"
rd /s /q "{app}\patch_003_out"
rd /s /q "{app}\patch_004_out"
rd /s /q "{app}\patch_005_out"
TIMEOUT 3
:End
endlocal

Using fast lolz preset it is 10.2GB compressed.

Keep in mind the game files will not be crc perfect after this step, but the game will work anyways.