existing script 8574 will support srep/precomp. just change to internal conversion.
Use compress.bat from any other conversion & in put into setup.ini
Code:
[ExtractSettings]
FreeArcFile1=Data1.cab;DestDir:{app};Disk:1;
FreeArcFile2=Data2.cab;DestDir:{app};Disk:1;
should be able to get it to fit on 1dvd5 then.