Tools for Repacking

[KaktoR]

HDD speeds (my m2 SSD is nearly full, so can't test)
chunk0.rpg (13.5 GB)
Unpack: 100% Done in 1181.58s
Repack: Scanning folder time 10min + 100% Done in 1141.25s

Edit:

Note: Disabled AV (Windows Defender) to speed up the whole process (it will give you a good speed boost).

M2 SSD
11:03:10 - Start
G:\test>rpkg-cli.exe -extract_from_rpkg "G:\chunk0.rpkg"
Extract from RPKG file: G:\chunk0.rpkg
Extract: All hash files with filter ""
Valid RPKGv2 file magic signature found.
RPKGv2 file chunk0.rpkg is not a patch file.
Importing index from RPKGv2 file: chunk0.rpkg
Importing RPKG file data: 100% Done in 2.5325s
Extracting from RPKG: 100% Done in 227.422s
11:07:01 - Stop

11:07:45 - Start
G:\test>rpkg-cli.exe -generate_rpkg_from "G:\Test\chunk0"
Using RPKG meta file: G:\Test\chunk0\chunk0.meta
Valid RPKGv2 file magic signature found.
RPKGv2 file G:\Test\chunk0\chunk0.meta is not a patch file.
Scanning folder: Done
Writing to temporary RPKG file: chunk0.rpkg.tmp
Generating RPKG file: 100% Done in 427.501s
Writing RPKGv2 offset index: 100% Done in 0.245895s
Writing RPKGv2 info index: 100% Done in 0.444143s
Merging RPKGv2 file and temporary RPKG files...
Merged RPKGv2 file and temporary RPKGv2 file in 130.196s
Successfully generated RPKGv2 file: chunk0.rpkg
11:17:34 - Stop

CRC Checks
Original CD516CCC
Repacked CD516CCC